central plaque of spindle pole body

description: One of three laminate structures that form the spindle pole body; the central plaque is embedded in the nuclear envelope.


cellular bud neck contractile ring

category: biolink:CellularComponent biolink:AnatomicalEntity biolink:PhysicalEssence biolink:OrganismalEntity biolink:SubjectOfInvestigation biolink:BiologicalEntity biolink:ThingWithTaxon biolink:NamedThing biolink:PhysicalEssenceOrOccurrent

description: A contractile ring, i.e. a cytoskeletal structure composed of actin filaments and myosin, that forms beneath the plasma membrane at the mother-bud neck in mitotic cells that divide by budding in preparation for completing cytokinesis. An example of this structure is found in Saccharomyces cerevisiae.


extrahaustorial matrix

description: The space between the symbiont plasma membrane and the extrahaustorial membrane of the host.


glyoxysomal membrane

description: The lipid bilayer surrounding a glyoxysome.


glycosome membrane

description: The lipid bilayer surrounding a glycosome.


nucleus lagging edge

description: The area of a motile nucleus furthest from the direction of movement.


mannosome

description: A specialised tubular organelle, assembled in hexagonal bundles within an external membrane. Mannosomes are specific to molluscs and are thought to be involved in a general stress reaction.


name: extrinsic component of postsynaptic specialization membrane

description: The component of the postsynaptic specialization membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


name: extrinsic component of presynaptic active zone membrane

description: The component of the presynaptic active zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


name: extrinsic component of synaptic membrane

description: The component of the synaptic membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


name: extrinsic component of postsynaptic endocytic zone

description: The component of the postsynaptic endocytic zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


bacterial microcompartment

description: An organelle found in bacteria consisting of a proteinaceous coat containing metabolic enzymes whose purpose is the sequestration or concentration of metabolites and which has the appearance of a polygonal granule by electron microscopy.


protein aggregate center

description: Reversible aggregate of misfolded proteins and chaperones formed to shield thermosensitive proteins from degradation until conditions allow disaggregation and refolding.


crystalloid

description: A transient, cytoplasmic organelle found in Plasmodium species that resembles a cytoplasmic inclusion body and whose function is poorly understood. Crystalloids form in ookinetes and disappear after ookinete-to-oocyst transformation.


arciform density

description: An electron dense structure that anchors a synaptic ribbon to the presynaptic membrane.


monolayer-surrounded lipid storage body

description: A subcellular organelle of plant cells surrounded by 'half-unit' or a monolayer membrane instead of the more usual bilayer. The storage body has a droplet of triglyceride surrounded by a monolayer of phospholipids, interacting with the triglycerides and the hydrophilic head groups facing the cytosol, and containing major protein components called oleosins.


mitochondrial chromosome

description: A chromosome found in the mitochondrion of a eukaryotic cell.


Z chromosome

description: The sex chromosome present in both sexes of species in which the female is the heterogametic sex. Two copies of the Z chromosome are present in each somatic cell of males and one copy is present in females.


spectrosome

description: A germline specific spherical organelle, rich in membrane skeletal proteins. Precursor to the fusome.


ascus lipid droplet

description: Any particle of coalesced lipids in an ascus or ascospore. May include associated proteins.


chloroplast nucleoid

description: The region of a chloroplast to which the DNA is confined.


chloroplast stromal thylakoid

description: Unstacked thylakoids that connect the grana stacks through the stroma.


plastid ribosome

description: A ribosome contained within a plastid.


pyrenoid

description: A non-membrane-bounded organelle found within the chloroplasts of algae and hornworts; responsible for carbon dioxide fixation.


carboxysome

description: An organelle consisting of a proteinaceous coat and enzymes for the fixation of CO2. It augments the concentration of CO2 in the vicinity of RuBisCO to increase the efficiency of CO2 fixation under atmospheric conditions.


bacterial nucleoid

description: The region of a bacterial cell to which the DNA is confined.


goblet cell theca

description: A cup shaped specialization of the cytoskeleton that forms a thin layer located just below the apical mass of mature mucin secretory granules in the cytoplasm of goblet cells of the intestinal epithelium. It consists of an orderly network of intermediate filaments and microtubules. Microtubules are arranged vertically, like barrel staves, along the inner aspect of the theta. Intermediate filaments form two networks: an inner, basketlike network and an outer series of circumferential bundles resembling the hoops of a barrel.


synaptic ribbon

description: A non-membrane bound, electron dense structure associated that extends perpendicular to the presynaptic membrane in ribbon synapses. The ribbon's surface is studded with small particles to which synaptic vesicles tether via fine filaments. The tethered vesicles function as a pool, several fold greater than the docked pool available for fast release, which supports sustained release of vesicles. Synaptic ribbons may be plate like or spherical.


proplastid nucleoid

description: The region of a proplastid to which the DNA is confined.


chloroplast thylakoid

description: Sac-like membranous structures (cisternae) in a chloroplast combined into stacks (grana) and present singly in the stroma (stroma thylakoids or frets) as interconnections between grana. An example of this component is found in Arabidopsis thaliana.


active sex chromosome

description: A sex chromosome that has not been inactivated.


polytene chromosome chromocenter

description: A region at which the centric regions of polytene chromosomes are joined together.


cyanelle thylakoid

description: A thylakoid found in a cyanelle, which is a type of plastid found in certain algae. The cyanelle contains a photosynthetic membrane resembling that of cyanobacteria.


organellar ribosome

description: A ribosome contained within a subcellular membrane-bounded organelle.


prothylakoid

description: Underdeveloped thylakoids found in etioplasts, lacking competent photosynthetic membranes. Rapidly develop into mature thylakoids in the presence of light.


bacterial thylakoid

description: A thylakoid that is derived from and attached to, but not necessarily continuous with, the plasma membrane, and is not enclosed in a plastid. It bears the photosynthetic pigments in photosynthetic cyanobacteria.


gas vesicle

description: An intracellular non-membrane-bounded organelle; a hollow structure made of protein, which usually has the form of a cylindrical tube closed by conical end caps. By regulating their relative gas vesicle content, aquatic microbes are able to perform vertical migrations.


nucleolus-like body

description: A nuclear compartment containing significant amounts of non-nucleolar, spliceosomal components. It is commonly found in germinal vesicle (GV) stage oocytes, and is similar to both nucleoli and sphere organelles.


thylakoid

description: A membranous cellular structure that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the plasma membrane. In eukaryotes they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.


organellar chromatophore thylakoid

description: A thylakoid located in an organellar chromatophore.


plastid thylakoid

description: Any thylakoid within a plastid.


plastid nucleoid

description: The region of a plastid to which the DNA is confined.


name: propanediol degradation polyhedral organelle

description: An organelle found in bacteria consisting of a proteinaceous coat containing enzymes for the degradation of 1,2-propanediol whose purpose is the protection of the rest of the cell from the toxic propionaldehyde product of the enzyme diol dehydratase.


chlorosome

description: A large enclosure of aggregated pigment, typically bacteriochlorophyll c (BChl c), that acts as a light-harvesting antenna structure and is characteristic of green photosynthetic bacteria (e.g. Chlorobiaceae). The BChl aggregates are organized into lamellar elements by pigment-pigment rather than pigment-protein interactions. Chlorosomes also contain BChl a, carotenoids, quinones, lipids, and proteins, and are attached to the cytoplasmic membrane via a BChl a-containing protein baseplate.


ventral disc

description: Specialized organelle found in Giardia species (trophozoite stage) and characterized by a spiral array of microtubules and microtubule-associated structures including dorsal microribbons and crossbridges. The edge of the ventral disc narrows into a lateral crest. The ventral disk mediates mechanical attachment of the trophozoite to the host's intestinal wall, and contains the contractile proteins actinin, alpha-actinin, myosin, and tropomyosin working towards contraction of the disk involved in adherence.


nematocyst

description: An organelle found in cnidoblast (nematoblast) cells. When matured, these stinging organelles store toxins and can deliver them when the cnidocil (a short extension of the cnidocyst) is stimulated by a prey or another stimulus.


W chromosome

description: The sex chromosome present in females of species in which the female is the heterogametic sex; generally, the sex chromosome that pairs with the Z chromosome in the heterogametic sex. The W chromosome is absent from the cells of males and present in one copy in the somatic cells of females.


blepharoplast

description: An intracellular non-membrane-bounded organelle found in multi-ciliated sperm cells of some primitive land plants, and consisting of many radially arranged ninefold symmetric cylinders. The blepharoplast is involved in de novo formation of multiple centrioles; it enlarges and then disintegrates into many procentrioles, which elongate and ultimately nucleate cilia on the surface of the sperm cell.


granal stacked thylakoid

description: Appressed thylakoid membranes that are part of a granum (stacked regions). A characteristic of these appressed regions is the preferential localization of photosystem II.


elaioplast

description: A leucoplast in which oil is stored.


mitotic nuclear bridge

description: A narrow constricted region of the nucleus that forms around the anaphase spindle during closed mitosis, and connects the main portions of the newly forming daughter nuclei.


host cell rough endoplasmic reticulum

description: The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host rough ER has ribosomes adhering to the outer surface.


name: extrinsic component of external side of mycolate outer membrane

description: The component of mycolate membrane consisting of gene products and protein complexes that are loosely bound to its external surface, but not integrated into the hydrophobic region.


name: extrinsic component of mycolate outer membrane

description: The component of mycolate outer membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


name: alae of collagen and cuticulin-based cuticle extracellular matrix

description: Raised, thickened cuticular ridges that run longitudinally, and in parallel, along the left and right sides of the animal. The alae lie above the hypodermal cells known as the lateral seam cells. In C. elegans, alae are produced in L1 larvae, dauer larvae and adult stage animals, where they consist of three, five, and three ridges of distinct morphology, respectively.


pnictogen molecular entity

A p-block molecular entity containing any pnictogen.


primary amide

A derivative of an oxoacid RkE(=O)l(OH)m (l =/= 0) in which an acidic hydroxy group has been replaced by an amino or substituted amino group.


amide

An amide is a derivative of an oxoacid RkE(=O)l(OH)m (l =/= 0) in which an acidic hydroxy group has been replaced by an amino or substituted amino group.


carboxamide

An amide of a carboxylic acid, having the structure RC(=O)NR2. The term is used as a suffix in systematic name formation to denote the -C(=O)NH2 group including its carbon atom.


organonitrogen compound

Any heteroorganic entity containing at least one carbon-nitrogen bond.


organic amino compound

A compound formally derived from ammonia by replacing one, two or three hydrogen atoms by organyl groups.


host multivesicular body

description: A late endosome in which regions of the limiting host cell endosomal membrane invaginate to form internal vesicles; host membrane proteins that enter the internal vesicles are sequestered from the host cytoplasm.


host cell late endosome

description: A prelysosomal endocytic organelle differentiated from host early endosomes by lower lumenal pH and different protein composition. Host late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center.


polar tube

description: A highly specialized structure unique to microsporidia that is required for host cell invasion. In the spore, the polar tube is connected at the anterior end, and then coils around the sporoplasm. Upon appropriate environmental stimulation, the polar tube rapidly discharges out of the spore, pierces a cell membrane and serves as a conduit for sporoplasm passage into the new host cell.


endospore coat

description: The layer in a bacterial endospore that lies under the exosporium, and is impermeable to many toxic molecules. The coat may also contain enzymes that are involved in endospore germination.


leucoplast stroma

description: The space enclosed by the double membrane of a leucoplast.


linear element

description: A proteinaceous scaffold associated with fission yeast chromosomes during meiotic prophase. Linear elements consist of a protein complex, LinE, with four main structural components (Rec10, Rec25, Rec27, and Mug20 in S. pombe) associated with chromatin. The resulting structure is related to but not equivalent to the synaptonemal complex.


amyloplast inner membrane

description: The inner, i.e. lumen-facing, lipid bilayer of the amyloplast envelope; also faces the amyloplast stroma.


megagametophyte egg cell nucleus

description: The nucleus of a plant egg cell. This nucleus is found at the micropylar end of the embryo.


lignin network

description: An extracellular matrix part that consists of lignin in the form of a three-dimensional polymeric network. Lignins are complex racemic aromatic heteropolymers derived from a variety of phenylpropane monomers coupled together by an assortment of carbon-carbon and ether linkages. Lignin is crucial for structural integrity of the cell wall and stiffness and strength of the stem. In addition, lignin waterproofs the cell wall, enabling transport of water and solutes through the vascular system, and plays a role in protecting plants against pathogens.


hyphal septin band

description: A septin band, i.e. a diffuse ring composed of a series of septin bars running parallel to the long axis of the cell, located at the junction between the mother cell and the germ tube (hypha) of a fungal cell growing filamentously.


pilus shaft

description: The long, slender, mid section of a pilus.


lower tip-link density

description: An electron-dense plaque at the lower end of a stereocilia tip link that provides the anchor in the stereocilia membrane at the tip of the stereocilium from which the tip link rises.


sieve area

description: A pit-like area in the cell wall of a sieve element; contains pores lined with callose and occupied by strands of protoplasmic material that interconnect the protoplasts of contiguous sieve elements.


host cell PML body

description: A nuclear body that reacts against SP100 auto-antibodies (PML = promyelocytic leukemia) located within a cell of a host organism.


nucleoplasmic side of nuclear pore

description: The side of the nuclear pore complex (NPC) that faces the nucleoplasm.


left lateral basal body pair

description: Set of two basal bodies found in Giardia species (trophozoite stage). It comprises the anterior and ventral basal bodies located to the right of the left nucleus of the trophozoite when viewed dorsally.


host cell centrosome

description: A structure in a host cell comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.


stereocilia tip link

description: A stereocilia link that is formed by a fine filament running more or less vertically upward from the tip of each shorter stereocilium to attach at a higher point on its adjacent taller neighbor. Tilting the bundle puts tension on the filaments, which pull on mechanically gated ion channels in the membrane of the stereocilia.


thorny excrescence

description: Large complex spine protruding from a dendrite. Each excrescence is formed by a cluster of spine heads.


postsynapse of neuromuscular junction

description: The postsynapse of a neuromuscular junction. In vertebrate muscles this includes the motor end-plate, consisting of postjunctional folds of the sarcolemma.


dinoflagellate sulcus

description: A cell surface furrow that occurs on the ventral side of a dinoflagellate cell. It partially houses the longitudinal flagellum. The sulcus intersects with the cingulum on the ventral side of a dinoflagellate cell.


cell surface furrow

description: A furrow that may be found on the cell surface. Examples include the cingulum and sulcus found in some dinoflagellates.


dinoflagellate cingulum

description: A cell surface furrow that wraps around a dinoflagellate cell; the transverse flagellum lies in it.


dinoflagellate sulcal notch

description: A dinoflagellate sulcus that extends all the way to the posterior end of the cell (also known as antapex). The presence of a sulcal notch makes the dinoflagellate hypocone appear bilobed.


dinoflagellate apical groove

description: A cell surface furrow (or groove) found on a dinoflagellate apex. It typically loops around the apex.


attachment organelle membrane

description: The lipid bilayer surrounding an attachment organelle. This is a region of the cell membrane facing the environment - in mycoplasma, part of the mycolate outer membrane.


host cell filopodium

description: Thin, stiff protrusion extended by the leading edge of a motile host cell such as a crawling fibroblast or amoeba, or an axonal growth cone; usually approximately 0.1 um wide, 5-10 um long, can be up to 50 um long in axon growth cones; contains a loose bundle of about 20 actin filaments oriented with their plus ends pointing outward.


host cell projection

description: A prolongation or process extending from a host cell, e.g. a flagellum or axon.


host cell uropod

description: A host cell membrane projection with related cytoskeletal components at the trailing edge of a cell in the process of migrating or being activated, found on the opposite side of the cell from the leading edge or immunological synapse, respectively.


T=219 icosahedral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=219 symmetry. T=219 icosahedral capsid is composed of 12 pentameric and 2180 hexameric capsomeres for a total of 13140 capsid proteins.


post-anaphase array microtubule end

description: Any microtubule end that is part of a post-anaphase array microtubule.


cytoplasmic microtubule minus-end

description: A microtubule minus end that is part of a cytoplasmic microtubule.


plasmodesmatal endoplasmic reticulum

description: Endoplasmic reticulum found in plasmodesmata, junctions connecting the cytoplasm of adjacent plant cells.


membrane stack

description: A configuration of endoplasmic reticulum (ER) found in Purkinje cells in the cerebellum and in axons in the lateral vestibular nucleus, consisting of parallel and interconnecting tubules whose outer surfaces are covered by particles or ringlike structures.


host intracellular part

description: Any constituent part of the living contents of a host cell; the matter contained within (but not including) the plasma membrane, usually taken to exclude large vacuoles and masses of secretory or ingested material. In eukaryotes it includes the nucleus and cytoplasm. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host chromosome

description: A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information, occurring within a host cell.


host cell nucleus

description: A membrane-bounded organelle as it is found in the host cell in which chromosomes are housed and replicated. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell synaptic vesicle

description: A secretory organelle of a host cell, some 50 nm in diameter, of presynaptic nerve terminals; accumulates in high concentrations of neurotransmitters and secretes these into the synaptic cleft by fusion with the 'active zone' of the presynaptic plasma membrane.


Maurer's cleft

description: A disk-like structure that appears at the periphery of a red blood cell infected by an apicomplexan parasite, characterized by a translucent lumen and an electron-dense coat of variable thickness; often appears to be tethered to the host cell membrane by fibrous connections with the erythrocyte cytoskeleton.


viral replication complex

description: Specific locations and structures in the virus infected cell involved in replicating the viral genome.


host cell nucleolus

description: A small, dense body one or more of which are present in the nucleus of eukaryotic host cells.


name: host cell mitochondrial intermembrane space

description: The region between the inner and outer lipid bilayers of the host cell mitochondrial envelope.


host cell plastid

description: Any member of a family of organelles as found in the cytoplasm of host cells, which are membrane-bounded and contain DNA. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell nucleoplasm

description: That part of a host cell's nuclear content other than the chromosomes or the nucleolus. The host is the larger of the organisms involved in a symbiotic interaction.


host symbiosome

description: A double-enveloped cell compartment, composed of the endosymbiont with its plasmalemma (as inner envelope) and an outer envelope (the perisymbiontic membrane) derived from the host cell.


host cell endoplasmic reticulum lumen

description: The volume enclosed by the membranes of the host cell endoplasmic reticulum.


host cell synaptic vesicle membrane

description: The lipid bilayer surrounding a host synaptic vesicle.


host cell nuclear lamina

description: The fibrous, electron-dense layer lying on the nucleoplasmic side of the inner membrane of a host cell nucleus, composed of lamin filaments.


host cell peroxisome

description: A small host cell organelle enclosed by a single membrane, and found in most eukaryotic cells. Contains peroxidases and other enzymes involved in a variety of metabolic processes including free radical detoxification, lipid catabolism and biosynthesis, and hydrogen peroxide metabolism.


host cell endosome lumen

description: The volume enclosed by the membranes of the host cell endosome.


host cell mitochondrion

description: A semiautonomous, self replicating organelle as found in host cells that occurs in varying numbers, shapes, and sizes in the cell cytoplasm. The host is defined as the larger of the organisms involved in a symbiotic interaction.


name: host cell perinuclear region of cytoplasm

description: The host cell cytoplasm situated near, or occurring around, the host nucleus.


host thylakoid membrane

description: The pigmented membrane of any host thylakoid.


host cell cytoplasmic vesicle

description: A vesicle formed of membrane or protein, found in the cytoplasm of a host cell.


host cell lysosome

description: A small lytic vacuole that has cell cycle-independent morphology and is found in most host animal cells and that contains a variety of hydrolases, most of which have their maximal activities in the pH range 5-6. The contained enzymes display latency if properly isolated. About 40 different lysosomal hydrolases are known and host cell lysosomes have a great variety of morphologies and functions.


host cell nuclear part

description: Any constituent part of a host cell's nucleus, a membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. The host is the larger of the organisms involved in a symbiotic interaction.


host cell lipid droplet

description: Any particle of coalesced lipids in the cytoplasm of a host cell. May include associated proteins.


host cell Cajal body

description: A class of nuclear body in the eukaryotic host cell, first seen after silver staining by Ramon y Cajal in 1903, enriched in small nuclear ribonucleoproteins, and certain general RNA polymerase II transcription factors; ultrastructurally, they appear as a tangle of coiled, electron-dense threads roughly 0.5 micrometers in diameter; involved in aspects of snRNP biogenesis; the protein coilin serves as a marker for Cajal bodies. Some argue that Cajal bodies are the sites for preassembly of transcriptosomes, unitary particles involved in transcription and processing of RNA. The host is the larger of the organisms involved in a symbiotic interaction.


host intracellular organelle

description: Organized structure of distinctive morphology and function, occurring within the host cell. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell smooth endoplasmic reticulum

description: The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host smooth ER has no ribosomes adhering to the outer surface.


host cell mitochondrial envelope

description: The double lipid bilayer enclosing the host cell mitochondrion and separating its contents from the host cell cytoplasm; includes the intermembrane space.


symbiont-containing vacuole

description: Membrane-bounded vacuole within a host cell in which a symbiont organism resides. The vacuole membrane is derived from both the host and symbiont.


host cytoskeleton

description: A cellular structure that forms the internal framework of eukaryotic and prokaryotic host cells. The cytoskeleton includes intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles.


host cell cytoplasmic vesicle membrane

description: The lipid bilayer surrounding a host cell cytoplasmic vesicle.


host cell endosome

description: A membrane-bounded organelle that carries materials newly ingested by endocytosis. It passes many of the materials to host cell lysosomes for degradation.


host cell nuclear matrix

description: The dense fibrillar network lying on the inner side of the host nuclear membrane.


name: double membrane vesicle viral factory lumen

description: The volume surrounded by the inner membrane of a double membrane vesicle viral factory.


host cell cytoplasm part

description: Any constituent part of the host cell cytoplasm, all of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell endoplasmic reticulum

description: The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached).


host cell cytosol

description: The part of the host cell cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.


host cell viral nucleoid

description: The region of a host cell that contains the viral genome.


name: host intracellular membrane-bounded organelle

description: Organized structure of distinctive morphology and function, as found in host cells, bounded by a single or double lipid bilayer membrane and occurring within the cell. Includes the nucleus, mitochondria, plastids, vacuoles, and vesicles. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host thylakoid

description: A membranous cellular structure within the host cell that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the host plasma membrane. In eukaryotic host cells they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.


T=pseudo3 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with pseudo T=3 symmetry. The T=pseudo3 capsid is composed of 12 pentameric and 20 hexameric capsomeres.


icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles; the subunits are arranged to form an icosahedron, a solid with 20 faces and 12 vertices. Icosahedral capsids have 12 pentamers plus 10(T-1) hexamers, where T is the triangulation number. Tobacco satellite necrosis virus has such a capsid structure.


T=147 icosahedral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=147 symmetry. T=147 icosahedral capsid is composed of 12 pentameric and 1460 hexameric capsomeres for a total of 8820 capsid proteins.


T=2 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=2 symmetry. The T=2 capsid is composed of 12 pentameric dimers.


T=31/pseudo31 icosahedral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=31 or pseudo T=31 symmetry.


T=27/pseudo27 icosahedral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=27 or pseudo T=27 symmetry.


T=169 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=169 symmetry. T=169 icosahedral capsid is composed of 12 pentameric and 1680 hexameric capsomeres for a total of 10140 capsid proteins.


T=16 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=16 symmetry. The T=16 capsid is composed of 12 pentameric and 150 hexameric capsomeres.


T=21/pseudo21 icosahedral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=21 or pseudo T=21 symmetry.


T=13 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=13 symmetry. The T=13 capsid is composed of 12 pentameric and 120 hexameric capsomeres.


T=25 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=25 symmetry. The T=25 capsid is composed of 12 pentameric and 240 hexameric capsomeres.


T=28 icosahedral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=28 symmetry.


T=3 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=3 symmetry. The T=3 capsid is composed of 12 pentameric and 20 hexameric capsomeres.


T=7 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=7 symmetry. The T=7 capsid is composed of 12 pentameric and 60 hexameric capsomeres.


T=4 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=4 symmetry. The T=4 capsid is composed of 12 pentameric and 30 hexameric capsomeres.


T=1 icosahedral viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=1 symmetry. The T=1 capsid is composed of 12 pentameric capsomeres.


name: postsynaptic specialization membrane of symmetric synapse

description: The membrane component of the postsynaptic specialization of a symmetric synapse. This is the region of the postsynaptic membrane in which the population of neurotransmitter receptors involved in synaptic transmission are concentrated.


nucleoid

description: The region of a virus, bacterial cell, mitochondrion or chloroplast to which the nucleic acid is confined.


type Ib terminal bouton

description: Terminal inflated portion of the axon of a glutamatergic neuron, containing the specialized apparatus necessary for the tonic release neurotransmitters that will induce the contraction of muscle. Type Ib terminal boutons are larger than type Is terminal boutons.


basal distal dendrite

description: Any dendrite in a dendritic tree that emerges near the basal pole of a neuron (e.g. in bipolar neurons, basal dendrites are either on the same side of the soma as the axon, or project toward the axon), and which is farthest away from the neuronal cell body (the soma).


cell wall-bounded periplasmic space

description: The region between the plasma membrane and the cell wall in organisms lacking an outer cell membrane such as yeast and Gram positive bacteria. The region is thinner than the equivalent in Gram negative bacteria.


name: monolayer-surrounded lipid storage body outer lipid monolayer

description: The single layer of phopholipids surrounding a lipid storage body.


left posteriolateral flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left posteriolateral basal body and extends cytoplasmically toward the cell posterior, marking the left anterior boundary of the lateral shield and the left lateral region of the funis before exiting at the left lateral region of the cell body.


hyphal tip

description: The end, or tip, of a fungal hypha, where polarized growth occurs during hyphal elongation.


nucleolar chromatin

description: The portion of nuclear chromatin associated with the nucleolus; includes the DNA encoding the ribosomal RNA.


nucleolus-associated heterochromatin

description: Dense particles of heterochromatin, consisting of a loosely twisted strand about 600 Angstrom thick, found associated with the nucleolus.


S bouton

description: Synaptic bouton found in the ventral horn of the spinal cord. S boutons range in diameter from 0.5 to 8 um and contain spherical synaptic vesicles.


smooth endoplasmic reticulum cisterna

description: A subcompartment of the smooth endoplasmic reticulum consisting of lumenal expansion into a flattened, disc-shaped cavity.


subrhabdomeral cisterna

description: A membrane-bounded compartment that is found at the base of the rhabdomere and contains stored calcium, InsP3 receptors and smooth endoplasmic reticulum Ca2+-ATPase.


sub-surface cisterna

description: Specialization of the hypolemmal cisterna consisting of either single profiles or closely apposed stacks of endoplasmic reticulum in which the lumen is obliterated, lying 10-20 nm beneath the plasma membrane.


hypolemmal cisterna

description: Specialized part of the smooth endoplasmic reticulum that closely underlies the plasma membrane, usually within 60 nm or closer.


ciliary pocket

description: Invagination of the plasma membrane from which a cilium (also called flagellum) protrudes.


eisosome membrane domain/MCC

description: A plasma membrane part that is composed of a furrow-like plasma membrane domain and associated integral transmembrane proteins.


host peribacteroid membrane

description: A host-derived membrane that surrounds one or more bacteroids (such as nitrogen-fixing bacteroids within legume root nodule cells).


transverse flagellum

description: A motile cilium found in dinoflagellates. It coils around the cell and provides the forward thrust for motility. It is often contained in a furrow called the cingulum, and emerges from a flagellar pore located in the cingulum.


sculpture element

description: The third layer of the sexine.


platelet glycocalyx

description: The carbohydrate rich layer at the outermost periphery of a platelet.


right tetrad

description: Set of four basal bodies found in Giardia species (trophozoite stage). It comprises the right lateral basal body pair and the right middle basal body pair (i.e. the anterior, ventral, caudal and posteriolateral basal bodies located to the left of the right nucleus of the trophozoite when viewed dorsally).


name: ventral disc supernumerary microtubule array

description: A partial left-handed spiral array of microtubules that lies generally dorsal to the main ventral disc microtubule array in Giardia species (trophozoite stage).


axonemal central pair

description: Part of the axoneme consisting of the inner two microtubule doublets of the 9+2 axoneme occurring in most motile cilia.


clathrin-coated endocytic vesicle lumen

description: The volume enclosed by the membrane of a clathrin-coated endocytic vesicle.


early phagosome lumen

description: The volume enclosed by the membrane of an early phagosome.


host cell surface

description: The external part of the host cell wall and/or host plasma membrane.


host apoplast

description: The apoplast region surrounding a host plant cell. Plants may be described as having two major compartments: the living symplast and the non-living apoplast. The apoplast is external to the plasma membrane and includes cell walls, intercellular spaces and the lumen of dead structures such as xylem vessels. Water and solutes pass freely through it. The host is defined as the larger of the organisms involved in a symbiotic interaction.


left ventral basal body

description: Any ciliary basal body that is part of a left ventral flagellum found in Giardia species (trophozoite stage).


respiratory system basement membrane

category: biolink:AnatomicalEntity biolink:PhysicalEssence biolink:OrganismalEntity biolink:SubjectOfInvestigation biolink:BiologicalEntity biolink:ThingWithTaxon biolink:NamedThing biolink:PhysicalEssenceOrOccurrent

description: A basement membrane of epithelium that is part of a respiratory system.


acellular membrane

description: An acellular anatomical structure that is the bounding layer of a anatomical structure.


organic molecular entity

Any molecular entity that contains carbon.


heteroorganic entity

A heteroorganic entity is an organic molecular entity in which carbon atoms or organic groups are bonded directly to one or more heteroatoms.


organochalcogen compound

An organochalcogen compound is a compound containing at least one carbon-chalcogen bond.


organooxygen compound

An organochalcogen compound containing at least one carbon-oxygen bond.


endospore-forming forespore

description: Portion of the cell formed during the process of bacterial sporulation that will ultimately become the core of the endospore. An endospore is a type of dormant cell that is resistant to adverse conditions.


inner layer of spore wall

description: Either of the two innermost layers of the spore wall, as described in Saccharomyces.


9+2 non-motile cilium

description: A non-motile cilium where the axoneme has a ring of nine outer microtubule doublets plus two central microtubules (and is therefore called a 9+2 axoneme).


granum

description: Distinct stack of lamellae seen within chloroplasts. Grana contain the pigments, electron transfer compounds, and enzymes essential to the light-dependent reactions of photosynthesis.


F bouton

description: Synaptic bouton found in the ventral horn of the spinal cord. F boutons range in diameter from 0.5 to 7 um and contain flattened or pleomorphic synaptic vesicles.


eisosome

description: A cell part that is composed of the eisosome membrane or MCC domain, a furrow-like plasma membrane sub-domain and associated integral transmembrane proteins, and the proteins (eisosome filaments) that form a scaffolding lattice on the cytoplasmic face. Eisosomes broadly affect overall plasma membrane organization.


description: Organized structure of distinctive morphology and function, not bounded by a lipid bilayer membrane and occurring outside the cell.


cellulosome

description: An extracellular multi-enzyme complex containing up to 11 different enzymes aligned on a non-catalytic scaffolding glycoprotein. Functions to hydrolyze cellulose.


mating projection base

description: The region where the mating projection meets the bulk of the cell, in unicellular fungi exposed to mating pheromone.


apoplast

description: The cell membranes and intracellular regions in a plant are connected through plasmodesmata, and plants may be described as having two major compartments: the living symplast and the non-living apoplast. The apoplast is external to the plasma membrane and includes cell walls, intercellular spaces and the lumen of dead structures such as xylem vessels. Water and solutes pass freely through it.


porous cell septum

description: A septum or cross wall which does not entirely span the space between two portions of cell wall and may contain a specialized central pore structure. A porous septum allows the movement of organelles and/or cytoplasm between compartments.


dolipore septum

description: A septum, or cross-wall, between two portions of a cell or hypha; contains a central pore around which the septum is swollen to form a barrel-shaped structure; pore is covered on each side of the septum by a septal pore cap (parenthosome).


host cell synapse

description: The junction between a nerve fiber of one host neuron and another host neuron or muscle fiber or glial cell; the site of interneuronal communication.


cellular bud neck septin structure

description: Any of a series of septin structures that are localized in the bud neck of a budding fungal cell during the cell cycle.


annular furrow extracellular matrix

description: The extracellular matrix part that is a regularly spaced indentation in the outer cortical layer of the cuticle. The pattern of annular furrows corresponds to sites of invaginations in hypodermal cell membranes that, in turn, correspond to submembranous regions where actin microfilament bundles assemble early in lethargus, the first phase of the molting cycle in which activity and feeding decline.


yolk granule

description: Discrete structures that partition the water-insoluble portion of the yolk of oocytes and ova, which may or may not be membrane enclosed.


name: symbiont-containing vacuolar membrane network

description: Tubular network of extensions from the symbiont-containing vacuole membrane that protrude into the host cytoplasm.


host cell plasma membrane

description: The plasma membrane surrounding a host cell.


pellicle

description: The structure enclosing certain parasite cells such as certain apicomplexa and Euglenozoa; consists of the cell membrane with its associated infrastructure of microtubules, microfilaments and other organelles.


dendritic tuft

description: The terminal specialization found in some types of dendrites which consists of numerous small terminal branches, giving the dendrite a tufted appearance.


peribacteroid fluid

description: The soluble material inside the peribacteroid membrane, but outside of the bacteroid, within a bacteroid-containing symbiosome.


spine synapse

description: A type of synapse occurring between an axon and a dendritic spine.


short microvillus layer

description: A layer of microvilli covering lymphocytes.


proximal convoluted tubule brush border

description: A brush border layer that is part of a proximal tubule in the kidney.


cellular bud scar

description: Crater-like ring of chitinous scar tissue located on the surface of the mother cell. It is formed after the newly emerged daughter cell separates thereby marking the site of cytokinesis and septation. The number of bud scars that accumulate on the surface of a cell is a useful determinant of replicative age.


host cell mitochondrial membrane

description: Either of the lipid bilayers that surround the host cell mitochondrion and form the host cell mitochondrial envelope.


host cell mitochondrial inner membrane

description: The inner, i.e. lumen-facing, lipid bilayer of the host cell mitochondrial envelope. It is highly folded to form cristae.


exopher

description: An extracellular vesicle that is approximately four microns in diameter, released by budding out of cells into the extracellular space, and hypothesized to be a mechanism for disposal of unwanted cellular material including protein aggregates and damaged organelles.


female germline ring canal outer rim

description: An electron opaque backbone of the insect ovarian ring canal that is a part of or adjacent to the plasma membrane. The outer rim is established as the cleavage furrow is arrested, and contains F-actin, anillin, glycoproteins and at least one a protein with a high content of phosphorylated tyrosine residues.


free sarcoplasmic reticulum membrane

description: The part of the sarcoplasmic reticulum membrane that contains calcium pumps and is devoted to calcium uptake. The free sarcoplasmic reticulum membrane consists of the longitudinal sarcoplasmic reticulum membrane and the non-junctional region of the terminal cisterna membrane.


filiform apparatus

description: A complex of cell wall invaginations in a synergid cell, similar to those in transfer cells.


endospore core

description: An intracellular part that represents the innermost portion of an endospore; the endospore core is dehydrated, enriched in dipicolinic acid and divalent cations, and metabolically inactive.


phagocytic cup lip

description: The tip or margin of the progressing circular lamella that engulfs a particle during phagocytosis. When the two lips of the cup fuse it is converted into a phagosome.


chlorosome envelope

description: The structure, composed of a monolayer of glycolipids with embedded proteins, that encloses the pigments and other contents of the chlorosome.


organelle-enclosing lipid monolayer

description: A lipid monolayer that surrounds and encloses an organelle.


microneme

description: A small, elongated secretory organelle that forms part of the apical complex, located along the main axis of an apicomplexan parasite cell within the extreme apical region and at the periphery under the inner membrane complex. Of the specialized secretory compartments identified in apicomplexans, micronemes discharge their contents first, during initial contact of the parasite's apical pole with the host cell surface. Micronemal proteins function during parasite attachment and penetration into the target cell.


magnetosome

description: A membrane-bound organelle that envelops particles of magnetic iron minerals in magnetotactic bacteria. Magnetosomes form linear chains that align along the cellular motility axis at midcell and function in bacterial navigation along the Earth's magnetic field. They are formed by invagination of the cell inner membrane; in some species they remain connected to the inner membrane, in others they pinch off to form independent intracellular vesicles.


dinoflagellate epicone

description: The part of a dinoflagellate cell above the cingulum; also referred to as the anterior portion of a dinoflagellate cell. It is separated from the hypocone by the cingulum.


p-block molecular entity

A main group molecular entity that contains one or more atoms of a p-block element.


chalcogen molecular entity

Any p-block molecular entity containing a chalcogen.


etioplast stroma

description: The space enclosed by the double membrane of an etioplast but excluding the prothylakoid space. It contains the etioplast DNA.


mating projection

description: The projection formed by unicellular fungi in response to mating pheromone.


ascus epiplasm

description: Ascus cytoplasm that is not packaged into ascospores.


phragmosome

description: A flattened membranous vesicle containing cell wall components.


eyespot apparatus

description: A small pigmented organelle used in single-celled organisms to detect light.


LYSP100-associated nuclear domain

description: A nuclear body that is enriched in the lymphoid cell-specific protein LYSp100B; LANDs are globular, electron-dense structures and are morphologically distinct from the annular structures characteristic of PML bodies.


omega speckle

description: A nucleoplasmic speckle distributed in the interchromatin space of cells in close proximity to chromatin. Omega speckles are distinct from interchromatin granules and contain heterogeneous nuclear RNA-binding proteins (hnRNPs).


nuclear dicing body

description: A small round nuclear body, measuring 0.2-0.8 microns in diameter that is diffusely distributed throughout the nucleoplasm. Several proteins known to be involved in miRNA processing have been localized to these structures. D-bodies are thought to be involved in primary-miRNA processing and/or storage/assembly of miRNA processing complexes.


sphere organelle

description: A nuclear body that is found in the germinal vesicles of amphibian oocytes, and consist of three major parts: a remarkably spherical body about 5-10 pm in diameter, smaller spherical or nearly spherical granules on the surface, and inclusions of various sizes that strongly resemble the surface granules. The parts of the sphere organelle have distinct compositions, including splicing snRNAs and proteins.


nuclear exosome focus

description: An nuclear body involved in nuclear mRNA surveilllance. Contains at least Mmi1, or an ortholog of it, and the nuclear exosome.


chromoplast stroma

description: The space enclosed by the double membrane of a chromoplast but excluding the photosynthetic material.


Golgi apparatus subcompartment

description: A compartment that consists of a lumen and an enclosing membrane, and is part of the Golgi apparatus.


apical proximal dendrite

description: The dendrite of the dendritic tree, which emerges near the apical pole of a neuron, and which is the closest to the cell body of the neuron (the soma).


helical viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles; the subunits are arranged to form a protein helix with the genetic material contained within. Tobacco mosaic virus has such a capsid structure.


right anterior flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It originates at the right anterior basal body, extends laterally through the cytoplasm, crosses the left anterior axoneme, and exits as a membrane-bound flagellum on the anterior right side of the cell.


germline ring canal

description: Germline specific intercellular bridge. During cyst formation in insects, ring canals interconnect the cells of the cyst, facilitating the passage of cytoplasmic components between cells.


female germline ring canal

description: An intercellular bridge that connects the germline cells of a female cyst.


male germline ring canal

description: An intercellular bridge that connects the germline cells of a male cyst.


vestibular calyx terminal

description: The giant, cup-shaped axon terminal of a vestibular afferent neuron, serving as a post-synaptic contact to a type I hair cell.


Herring body

description: The dilated terminal portions of neurosecretory axons constituting the hypothalamohypophyseal tract, found in close proximity to sinusoidal capillaries in the posterior pituitary. Herring bodies consist of aggregates of membrane-bound neurosecretory vesicles where oxytocin or antidiuretic hormone (ADH) are stored prior to release. Each Herring body also contains ATP and either neurophysin I or neurophysin II which bind to oxytocin and ADH, respectively.


P2 peroxisome

description: A subform of peroxisome that corresponds to an intermediate in a peroxisome assembly pathway, which operates by conversion of peroxisomal subforms in the direction P1, P2 -> P3 -> P4 -> P5 -> P6. P2 peroxisomes are distinguished from the other subforms on the bases of buoyant density and protein content; they are the least dense of the subforms observed.


oral apparatus

description: Complex basket- or funnel-like structure used by the cell to collect food and channel it to the cytostome; includes specialized sub-structures made up of closely-spaced cilia and underlying basal bodies and fibrillar systems.


cell trailing edge membrane

description: The portion of the plasma membrane surrounding the trailing edge of a motile cell.


fungal-type vacuole

description: A vacuole that has both lytic and storage functions. The fungal vacuole is a large, membrane-bounded organelle that functions as a reservoir for the storage of small molecules (including polyphosphate, amino acids, several divalent cations (e.g. calcium), other ions, and other small molecules) as well as being the primary compartment for degradation. It is an acidic compartment, containing an ensemble of acid hydrolases. At least in S. cerevisiae, there are indications that the morphology of the vacuole is variable and correlated with the cell cycle, with logarithmically growing cells having a multilobed, reticulated vacuole, while stationary phase cells contain a single large structure.


reservosome

description: A large membrane-bound endocytic organelle present only in members of the Schizotrypanum subgenus of the Trypanosoma genus and is defined as the site of storage of endocytosed macromolecules and lysosomal enzymes. It is found at the posterior end of epimastigote forms of Trypanosoma cruzi, but absent in amastigotes and trypomastigotes.


stigma papilla

description: A plant cell papilla that is part of a stigma papilla cell.


apical lamina of hyaline layer

description: A fibrous network that is part of the hyalin layer extracellular matrix. The apical lamina is thought to be principally composed of the glycoproteins fibropellins. This matrix has been found in echinoderms.


reservosome membrane

description: The lipid bilayer surrounding a reservosome.


left ventral flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left ventral basal body and exits the cell body proximally and dorsal to the ventral disc.


growth cone lamellipodium

description: A thin sheetlike process extended by the leading edge of an axonal or dendritic growth cone; contains a dense meshwork of actin filaments.


rod spherule

description: A specialized neuron projection which is the site of synaptic transmission produced by retinal rod cells. Rod spherules are small round enlargements of the axon (3-5 micrometers diameter) or even extensions of the cell body.


right posteriolateral flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right posteriolateral basal body and extends cytoplasmically toward the cell posterior, marking the right anterior boundary of the lateral shield and the right lateral region of the funis before exiting at the right lateral region of the cell body.


giant axon

description: Extremely large, unmyelinated axon found in invertebrates. Has high conduction speeds and is usually involved in panic or escape responses.


dendritic cell dendrite

description: A branched cellular projection (or cytoplasmic extension) that is extended from the surface of a dendritic immune cell, and which enables the cell to sample luminal pathogens and increase the surface area for antigen presentation to T cells.


rod telodendria

description: Rod telodendria are projections that originate from the rod pedicle and form gap junctions with other photoreceptors within the outer plexiform layer of the retina.


accessory outer segment

description: A cilium-like cell projection emanating from the inner segment and running alongside the outer segment of photoreceptors.


cone telodendria

description: Cone telodendria are projections that originate from the cone pedicle and form gap junctions with other photoreceptors within the outer plexiform layer of the retina.


muscle cell projection

description: A prolongation or process extending from a muscle cell. A muscle cell is a mature contractile cell, commonly known as a myocyte. This cell has as part of its cytoplasm myofibrils organized in various patterns.


cytoneme

description: A long, thin, polarized cell projection that contains actin and can extend for distances many times the diameter of the cell. Cytonemes represent extensions of cell cytoplasm and typically have a diameter of approximately 0.2um.


right ventral flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right ventral basal body and exits the cell body proximally and dorsal to the ventral disc.


pollen tube

description: A tubular cell projection that is part of a pollen tube cell and extends from a pollen grain.


right caudal flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right caudal basal body, extending cytoplasmically and exiting at the posterior end of the cell body.


left anterior flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It originates at the left anterior basal body, extends laterally through the cytoplasm, crosses the right anterior axoneme, and exits as a membrane-bound flagellum on the anterior left side of the cell.


gemmule

description: Spine-like process found on some neurons, e.g., periglomerular cells of olfactory cortex.


podocyte primary projection

description: A cell projection originating from a renal glomerular podocyte and extending to the renal glomerular podocyte foot.


rhabdomere microvillus

description: Thin cylindrical membrane-covered projection on the surface of a rhabdomere.


left caudal flagellum

description: A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left caudal basal body, extending cytoplasmically and exiting at the posterior end of the cell body.


cell hair

description: A long, thin cell projection that contains F-actin and tubulin, with microtubules centrally located and F-actin peripherally located.


longitudinal flagellum

description: A motile cilium found in dinoflagellates. It trails the cell and acts as a steering rudder. It is often partially contained in a furrow called the sulcus, and emerges from a flagellar pore located in the sulcus.


telodendria

description: Telodendria are projections that originate from the axon pedicle and form gap junctions with other neurons.


basal proximal dendrite

description: Any dendrite in a dendritic tree that emerges near the basal pole of a neuron (e.g. in bipolar neurons, basal dendrites are either on the same side of the soma as the axon, or project toward the axon), and which is the closest to the cell body of the neuron (the soma).


rhabdomere

description: The specialized microvilli-containing organelle on the apical surfaces of a photoreceptor cell containing the visual pigment rhodopsin and most of the proteins involved in phototransduction.


dinoflagellate peduncle

description: A small, flexible, finger-like projection of cytoplasm containing an array of microtubles and located near the flagellar pores in some photosynthetic as well as nonphotosynthetic dinoflagellate species. Its functions are not fully understood, but it has been associated with feeding behavior (phagotrophy).


plastid

description: Any member of a family of organelles found in the cytoplasm of plants and some protists, which are membrane-bounded and contain DNA. Plant plastids develop from a common type, the proplastid.


phenyloplast

description: A chloroplast-derived plastid in which the solid form of phenol is stored.


chloroplast

description: A chlorophyll-containing plastid with thylakoids organized into grana and frets, or stroma thylakoids, and embedded in a stroma.


apicoplast

description: The plastid organelle found in apicomplexans.


etioplast

description: A plastid arrested in the development of chloroplasts from proplastids due to absence of light or low light conditions.


leucoplast

description: A colorless plastid involved in the synthesis of monoterpenes.


chromoplast

description: A plastid containing pigments other than chlorophyll, usually yellow and orange carotenoid pigments.


proteinoplast

description: A leucoplast in which protein is stored.


cyanelle

description: A plastid that contains unstacked, phycobilisome-bearing thylakoid membranes and is surrounded by a double membrane with a peptidoglycan layer in the intermembrane space between the two envelope membranes. Cyanelles are characteristic of algae in the class Glaucophyta, and may represent an ancestral form of plastid.


cell plate

description: The nascent cell membrane and cell wall structure that forms between two daughter nuclei near the center of a dividing plant cell. It develops at the equatorial region of the phragmoplast. It grows outwards to join with the lateral walls and form two daughter cells.


egg chorion

description: A protective, noncellular membrane that surrounds the eggs of various animals including insects and fish.


viral capsid

description: The protein coat that surrounds the infective nucleic acid in some virus particles. It comprises numerous regularly arranged subunits, or capsomeres.


primary lysosome

description: A lysosome before it has fused with a vesicle or vacuole.


ascospore-type prospore nucleus

description: Any nucleus that is part of a ascospore-type prospore.


coated membrane

description: A single or double lipid bilayer with any of several different proteinaceous coats that can associate with membranes. Membrane coats include those formed by clathrin plus an adaptor complex, the COPI and COPII complexes.


bacterial-type flagellum filament

description: The long (approximately 20 nm), thin external structure of the bacterial-type flagellum, which acts as a propeller.


dendritic spine origin

description: The part of the dendritic spine neck where the spine arises from the dendritic shaft.


archaeal-type flagellum

description: A non-membrane-bounded organelle superficially similar to a bacterial-type flagellum; they both consist of filaments extending outside the cell, and rotate to propel the cell, but the archaeal flagella (also called archaella) have a unique structure which lacks a central channel. Similar to bacterial type IV pilins, the archaeal flagellins (archaellins) are made with class 3 signal peptides and they are processed by a type IV prepilin peptidase-like enzyme. The archaellins are typically modified by the addition of N-linked glycans which are necessary for proper assembly and/or function.


cellular anatomical entity

description: A part of a cellular organism that is either an immaterial entity or a material entity with granularity above the level of a protein complex but below that of an anatomical system. Or, a substance produced by a cellular organism with granularity above the level of a protein complex.


ventral disc overlap zone

description: A region of the ventral disc of Giardia species (trophozoite stage) where two portions of the same array of microtubules overlap (the microtubule array makes a complete circle and overlaps on itself).


pollen tube tip

description: The region at growing end of the pollen tube cell, where polarized growth occurs.


extrachromosomal rDNA circle

description: Circular DNA molecules encoding ribosomal RNA that are replicated independently of chromosomal replication. These molecules originate in the chromosome but are excised and circularized, often by intramolecular homologous recombination between direct tandem repeats.


medial membrane band

description: A sterol-rich region of the plasma membrane which forms at the cell surface overlying the contractile ring and spreads into the invaginating plasma membrane surrounding the septum.


somatic portion of tanycyte

description: Portion of a tanycyte that lies within the ependyma and contains the nucleus. A tanycyte is a specialized elongated ventricular ependymal cell that has processes that extend to the outer, or pial, surface of the CNS.


subsynaptic reticulum

description: An elaborate tubulolamellar membrane system that underlies the postsynaptic cell membrane.


plant cell papilla

description: A cell projection that is a short, rounded projection from a plant epidermal cell.


tail portion of tanycyte

description: Elongated process of a tanycyte, devoid of cytoplasmic extensions, that courses through the hypothalamic nuclei to form small endfoot processes that terminate either on blood vessels or at the pial surface of the brain. A tanycyte is a specialized elongated ventricular ependymal cell.


name: axonemal microtubule doublet outer junction

description: The structure which joins the B1 protofilament of the B tubule to the A10 and A11 protofilaments of the A tubule within an axonemal microtubule doublet.


bacterial-type flagellum basal body

description: One of the three major substructures of the bacterial-type flagellum, the basal body is embedded in the cell envelope (the plasma membrane, peptidoglycan cell wall, and, if one is present, the outer membrane); it houses the secretion apparatus that exports the more distal components and the flagellar motor.


yeast-form cell wall

description: The wall surrounding a cell of a dimorphic fungus growing in the single-cell budding yeast form, in contrast to the filamentous or hyphal form.


host cell plasmodesma

description: A fine cytoplasmic channel, found in all higher plants, that connects the cytoplasm of one host cell to that of an adjacent host cell.


contractile actin filament bundle

description: An actin filament bundle in which the filaments are loosely packed (approximately 30-60 nm apart) and arranged with opposing polarities; the loose packing allows myosin (usually myosin-II) to enter the bundle.


extrahaustorial membrane

description: The membrane surrounding the symbiont haustorium during symbiosis, derived from the host plasma membrane.


ectexine

description: The outer part of the exine, which stains positively with basic fuchsin in optical microscopy and has higher electron density in conventionally prepared TEM sections.


periphagosomal region of cytoplasm

description: Cytoplasm situated near, or occurring around, a phagosome.


actin body

description: An amorphous cytoskeletal structure consisting of aggregated actin filaments and associated proteins (including fibrin and capping protein) in which there is little or no actin filament turnover. In yeast (S. pombe and S. cerevisiae) these are found only in quiescent cells and are thought to serve as a reserve store of actin.


karyomere

description: A membrane-bound intermediate cleavage-stage structure of individual or groups of chromosomes that coalesces and fuses with other karyomeres to form a nucleus during interphase. Karyomere formation occurs in blastomeres undergoing rapid cell division.


actin tubule

description: A cellular structure, approximately 13 nm in diameter, consisting of three actin filaments bundled together.


old cell pole

description: The cell pole distal from the most recent cell division.


pathogen-containing vacuole membrane

description: Host-derived membrane of a pathogen-containing vacuole.


bacterial-type flagellum hook

description: The portion of the bacterial-type flagellum that connects the filament to the basal body.


new cell pole

description: The cell pole proximal to the most recent cell division.


thylakoid lumen

description: The volume enclosed by a thylakoid membrane.


name: mitotic actomyosin contractile ring, intermediate layer

description: The region of the mitotic actomyosin ring in between the proximal layer and the actin filament layer. This region contains the accessory protein network, some actin filaments and connections between the proximal layer and the actin filament layer.


hemicellulose network

description: Network composed of hemicelluloses; members of a class of plant cell wall polysaccharide that cannot be extracted from the wall by hot water or chelating agents, but can be extracted by aqueous alkali. Includes xylan, glucuronoxylan, arabinoxylan, arabinogalactan II, glucomannan, xyloglucan and galactomannan.


description: A membrane-bounded flattened sac that is formed during micropexophagy between the membrane tips of an engulfing vacuole, completing the engulfment and sequestration of peroxisomes from the cytosol, and forming a micropexophagic body within the lumen of the vacuole.


generative cell nucleus

description: The nucleus of the generative cell, a cell contained within the pollen grain that will divide to produce two haploid sperm cells.


P6 peroxisome

description: A subform of peroxisome that corresponds to an intermediate in a peroxisome assembly pathway, which operates by conversion of peroxisomal subforms in the direction P1, P2 -> P3 -> P4 -> P5 -> P6. P6 peroxisomes are distinguished from the other subforms on the bases of buoyant density and protein content, and are equivalent to mature peroxisomes.


name: microtubule organizing center attachment site

description: A region of the nuclear envelope to which a microtubule organizing center (MTOC) attaches; protein complexes embedded in the nuclear envelope mediate direct or indirect linkages between the microtubule cytoskeleton and the nuclear envelope.


polyadic synapse

description: A synapse consisting of a single presynapse and multiple postsynapses. These postsynapses may come from the same cell of from different cells. Polyadic synapses are common in arthropod and nematode central nervous systems.


mating projection membrane

description: The portion of the plasma membrane surrounding a mating projection, the projection formed by unicellular fungi in response to mating pheromone.


methane-oxidizing organelle

description: A cytoplasmic, membrane-bounded compartment found within Methanotrophic bacteria that contains enzymes and electron transfer proteins for methane catabolism. This structure is analogous to the thylakoid of Cyanobacteria and the anammoxosome of anaerobic ammonium oxidation organisms.


cleavage apparatus septin structure

description: Any of a series of structures composed of septins and septin-associated proteins localized to the cleavage plane which are involved in cytokinesis.


name: lytic vacuole within protein storage vacuole

description: A membrane-bounded compartment containing crystals of phytic acid and proteins characteristic of a lytic vacuole, found within a storage vacuole.


ciliary cap

description: An intracellular compartmentalized cilium structure found in insect spermatids which is bounded by a membrane derived from the invagination of the cell membrane that remains associated with the primary cilium as it is internalized. The ciliary cap is maintained at the end of the axoneme distal to the centriole and is separated from the cytosolic axoneme/cytoplasm by a putative transition zone, which may extend into the ciliary cap, and include a structure at the base of the ciliary cap termed the ring centriole.


host extracellular space

description: The space within a host but external to the plasma membrane of host cells, e.g. within host bloodstream.


female germline ring canal inner rim

description: A proteinaceous actin-rich layer of the insect ovarian ring canal that forms subcortically to the outer rim. The electron dense inner rim accumulates after the final mitotic division of each germline syncytia, and contains actin, a phosphotyrosine protein, and a number of cytoskeletal proteins.


name: cortical layer of collagen and cuticulin-based cuticle extracellular matrix

description: The cuticle layer that lies directly beneath the lipid-containing epicuticle. The cortical layer contains collagens and insoluble, non-collagenous cuticulins and is characterized by a distinct annular pattern consisting of regularly spaced annular ridges delineated by annular furrows. An example of this component is found in Caenorhabditis elegans.


ascospore-type prospore

description: An immature spore undergoing development. The spore usually consists of nucleic acid, prospore membrane(s) that encase the nucleic acid, and ultimately a cell wall that covers the membrane(s). This type of spore is observed in ascospore-forming fungi.


exosporium

description: The outermost layer of a bacterial endospore, which is loosely attached and located outside of the endospore coat. It is generally composed of protein, carbohydrate, and perhaps lipid.


mitotic actomyosin contractile ring

description: A cytoskeletal structure composed of actin filaments, myosin, and myosin-associated proteins that forms beneath the plasma membrane of many cells, including animal cells and yeast cells, in a plane perpendicular to the axis of the mitotic spindle, i.e. the cell division plane. Ring contraction is associated with centripetal growth of the membrane that divides the cytoplasm of the two future daughter cells. In animal cells, the mitotic contractile ring is located inside the plasma membrane at the location of the cleavage furrow. In budding fungal cells, e.g. mitotic S. cerevisiae cells, the mitotic contractile ring forms beneath the plasma membrane at the mother-bud neck before mitosis.


multiple synapse bouton

description: A single axon terminal bouton making contact onto two or more dendritic spines protruding either from a single dendrite or from multiple dendrites.


cellular bud membrane

description: The portion of the plasma membrane surrounding a cellular bud.


intracellular organelle lumen

description: An organelle lumen that is part of an intracellular organelle.


microbody lumen

description: The volume enclosed by the membranes of a microbody.


extracellular core region of desmosome

description: The desmosomal part containing the desmosomal cadherins, desmogleins and desmocollins, that establish contact and adhere to neighboring cells in a Ca2+-dependent manner.


amyloplast starch grain

description: Plant storage body for amylose and amylopectin, 1-100um in diameter, and located in amyloplasts. Also contains small amounts of enzymes, amino acids, lipids and nucleic acids. The shape of the grain varies widely amongst species, but is often spherical or disk-shaped.


host cell wall

description: The rigid or semi-rigid envelope lying outside the host cell membrane of plant, fungal, and most prokaryotic cells, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan.


plastid intermembrane space

description: The region between the inner and outer lipid bilayers of the plastid envelope.


mating projection tip membrane

description: The portion of the plasma membrane surrounding a mating projection tip.


name: mitotic spindle pole body attachment site

description: A region of the nuclear envelope to which a spindle pole body (SPB) attaches; protein complexes embedded in the nuclear envelope mediate direct or indirect linkages between the microtubule cytoskeleton and the nuclear envelope.


rhabdomere microvillus membrane

description: The portion of the plasma membrane surrounding a microvillus of a rhabdomere.


spore inner membrane

description: The membrane surrounding the spore core (endospore core) that separates it from its external environment.


cell wall

description: The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, most prokaryotic cells and some protozoan parasites, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan; in protozoan parasites such as Giardia species, it's made of carbohydrates and proteins.


host cellular component

description: Any cellular component of a host cell. The host is an organism in which another organism, for instance a parasite or symbiont, spends part or all of its life cycle and from which it obtains nourishment and/or protection.


mitochondrial inner boundary membrane

description: The portion of the mitochondrial inner membrane that is not invaginated to form cristae. The inner boundary membrane lies parallel to the outer membrane.


macropinocytic cup cytoskeleton

description: The part of the cortical actin cytoskeleton that forms part of a macropinocytic cup.


name: bacterial-type flagellum basal body, MS ring

description: One of the rings of the bacterial-type flagellar basal body; a double-flanged ring that anchors the basal body to the cytoplasmic membrane.


pilus

description: A proteinaceous hair-like appendage on the surface of bacteria ranging from 2-8 nm in diameter.


pairing center

description: A special chromosome region located towards one end of a chromosome that contains dispersed copies of short, repetitive DNA sequences and functions as a cis-acting element essential for presynaptic homologous chromosome pairing and chromosome-nuclear envelope attachment.


nucleomorph

description: A small, vestigial nucleus found in some plastids that derive from a eukaryotic endosymbiont. Observed in chlorarachniophytes and cryptomonads, which acquired their plastids from a green and red alga respectively.


Gram-positive-bacterium-type cell wall

description: A layer of peptidoglycan found outside of the cytoplasmic membrane. The peptidoglycan is relatively thick (20-80nm) and retains the primary stain of the Gram procedure, thus cells appear blue after Gram stain. The cell walls often contain teichoic acids (acidic anionic polysaccharides) bound to the peptidoglycan. Examples of this component are found in Gram-positive bacteria.


microsporocyte nucleus

description: The nucleus of the microsporocyte. The microsporocyte is a diploid cell in which meiosis will occur, resulting in four microspores. A microspore is a spore that, in vascular plants, gives rise to a male gametophyte.


division septum

description: A cell septum which forms as part of the division site and functions in the compartmentalization of a cell into two daughter cells at division. A division septum spans a cell and does not allow exchange of organelles or cytoplasm between compartments.


ensheathing process

description: A cell projection (often from glial cells such as Schwann cells) that surrounds an unmyelinated axon or cell soma.


microbody

description: Cytoplasmic organelles, spherical or oval in shape, that are bounded by a single membrane and contain oxidative enzymes, especially those utilizing hydrogen peroxide (H2O2).


bacterial outer membrane vesicle

description: A spherical, bilayered proteolipid vesicle released from gram-negative bacterial outer membranes.


type I terminal bouton

description: Terminal inflated portion of the axon of a glutamatergic neuron, containing the specialized apparatus necessary to release neurotransmitters that will induce the contraction of muscle. The axon terminus is considered to be the whole region of thickening and the terminal bouton is a specialized region of it.


fungal-type cell wall

description: A rigid yet dynamic structure surrounding the plasma membrane that affords protection from stresses and contributes to cell morphogenesis, consisting of extensively cross-linked glycoproteins and carbohydrates. The glycoproteins may be modified with N- or O-linked carbohydrates, or glycosylphosphatidylinositol (GPI) anchors; the polysaccharides are primarily branched glucans, including beta-linked and alpha-linked glucans, and may also include chitin and other carbohydrate polymers, but not cellulose or pectin. Enzymes involved in cell wall biosynthesis are also found in the cell wall. Note that some forms of fungi develop a capsule outside of the cell wall under certain circumstances; this is considered a separate structure.


name: multiple synapse bouton, contacting multiple dendrites

description: A single axon terminal bouton making contact onto two or more dendritic spines protruding from multiple dendrites.


host cell membrane pore complex

description: Any small opening in a host cell membrane that allows the passage of gases and/or liquids, composed of host proteins.


mitotic nuclear bridge midzone

description: The central region of a mitotic nuclear bridge, distal to the main portions of the daughter nuclei.


pellicular membrane

description: The portion of the plasma membrane surrounding the pellicle, a structure enclosing some parasite cells such as certain apicomplexa and Euglenozoa. These membranes are associated with an infrastructure of microtubules, microfilaments, and other organelles.


polytene chromosome ectopic fiber

description: A thread-like connection joining two regions of ectopically paired polytene chromosomes.


right ventral basal body

description: Any ciliary basal body that is part of a right ventral flagellum found in Giardia species (trophozoite stage).


microneme membrane

description: The lipid bilayer surrounding a microneme.


phragmoplast

description: The phragmoplast is a plant cell specific cytoplasmic structure composed of cytoskeletal polymers, membranes, and associated cytosolic proteins that functions as the focused secretory module for assembling the cell plate.


chloroplast inner membrane

description: The inner, i.e. lumen-facing, lipid bilayer of the chloroplast envelope; also faces the chloroplast stroma.


ventral surface of cell

description: The surface of a migrating cell that is in contact with the substratum or cell layer.


glycocalyx

description: A carbohydrate rich layer at the outermost periphery of a cell.


micronucleus

description: A membrane-bounded organelle of ciliated protozoan cells that contains a diploid copy of the cell's complete genome. Sections of contiguous sequence in the macronucleus are often interrupted by internal eliminated sequences (IES), and may be permuted, in micronuclei. Genic transcription is not found in micronuclei. Some ciliate species may contain multiple micronuclei per cell.


name: bacterial-type flagellum basal body, proximal rod

description: The portion of the central rod of the bacterial-type flagellar basal body that is proximal to the cell membrane; the proximal rod connects the distal rod to the flagellar motor.


plant-type cell wall

description: A more or less rigid structure lying outside the cell membrane of a cell and composed of cellulose and pectin and other organic and inorganic substances.


chrorion micropyle

description: A single cone-shaped specialization that forms an opening in the egg chorion that allows sperm entry into the egg prior to fertilization.


pirellulosome

description: A cytoplasmic structure found in bacterial phyla Planctomycetes and Verrucomicrobia containing a condensed nucleoid and ribosomes and surrounded by an intracytoplasmic membrane. It is surrounded by ribosome-free cytoplasm, in a compartment called the paryphoplasm.


dinoflagellate antapex

description: The anterior most point of a dinoflagellate hypocone.


glycosome

description: A membrane-bounded organelle found in organisms from the order Kinetoplastida that houses the enzymes of glycolysis.


plasmodesmatal cytoplasmic sleeve

description: The space between the plasma membrane and the desmotubule of a plasmodesma.


concave side of sperm head

description: The concave part of the late spermatid head or spermatozoon head that forms the ventral portion of the head, particularly in some rodent species.


microsporidian-type endospore

description: The middle layer in a microsporidian spore wall that lies under the exospore and outside the plasma membrane, containing chitin and proteins.


actin wave

description: A cellular anatomical entity that is part of the actin cytoskeleton and results in a wave-like propagation of actin networks. It consists of dynamic structures traveling on the ventral (substrate-attached) side of the cell during cell migration, cytokinesis, adhesion and neurogenesis.


type II terminal bouton

description: Terminal inflated portion of the axon of a non-glutamatergic neuron, containing the specialized apparatus necessary to release neurotransmitters at a regulatory synapse. The axon terminus is considered to be the whole region of thickening and the terminal bouton is a specialized region of it.


periarbuscular membrane

description: A host-derived membrane surrounding the symbiont arbuscule during symbiosis.


dinoflagellate apex

description: The anterior most point of a dinoflagellate epicone.


symbiont-containing vacuole membrane

description: The lipid bilayer surrounding a symbiont-containing vacuole, derived from both the host and symbiont.


ciliary microtubule quartet

description: A set of four specialized microtubules that originates from the basal bodies and wraps around the ciliary pocket membrane, likely supporting its distinct flask shape.


scintillon

description: A body present in the cytoplasm of some dinoflagellates, which is the source of bioluminescence; emits light on acidification in the presence of oxygen.


P3 peroxisome

description: A subform of peroxisome that corresponds to an intermediate in a peroxisome assembly pathway, which operates by conversion of peroxisomal subforms in the direction P1, P2 -> P3 -> P4 -> P5 -> P6. P3 peroxisomes are formed by fusion of P1 and P2 peroxisomes, and are distinguished from the other subforms on the bases of buoyant density and protein content.


name: surface coat of collagen and cuticulin-based cuticle extracellular matrix

description: An electron dense, amorphous envelope that comprises the outermost layer of the cuticle. The surface coat is loosely apposed to the epicuticle, has distinct biochemical properties, is synthesized by cells other than the underlying hypodermis, and is labile. In addition to serving as a lubricant to protect against abrasion and dehydration, the surface coat may also play important roles in infection and immune evasion. An example of this component is found in Caenorhabditis elegans.


name: nuclear envelope adjacent to nuclear pore complex

description: The region of the nuclear envelope situated in close proximity to a nuclear pore complex.


rod photoreceptor disc lumen

description: The volume enclosed by the membrane of a rod photoreceptor cell disc membrane.


leaflet of membrane bilayer

description: Any of the two layers of lipid molecules that constitute a membrane.


host cell endomembrane system

description: A collection of membranous structures involved in transport within the host cell. The main components of the endomembrane system are endoplasmic reticulum, Golgi bodies, vesicles, cell membrane and nuclear envelope. Members of the endomembrane system pass materials through each other or though the use of vesicles. The host is defined as the larger of the organisms involved in a symbiotic interaction.


name: extrinsic component of periplasmic side of cell outer membrane

description: The component of the cell outer membrane consisting of gene products and protein complexes that are loosely bound to periplasmic surface, but not integrated into the hydrophobic region.


nucleus leading edge

description: The area of a motile nucleus closest to the direction of movement.


dendritic knob

description: The terminal swelling of an apical dendrite of a ciliated olfactory receptor neuron. Each knob gives rise to 5 to 20 long delicate nonmotile cilia, which extend into the mucus covering the sensory epithelium.


chloroplast stroma

description: The space enclosed by the double membrane of a chloroplast but excluding the thylakoid space. It contains DNA, ribosomes and some temporary products of photosynthesis.


perforation plate

description: A cell wall part that is the part of a wall of a vessel member and bears one or more openings (perforations).


pathogen-containing vacuole lumen

description: The enclosed volume within the sealed membrane of a pathogen-containing vacuole.


sperm glycocalyx

description: The carbohydrate rich layer at the outermost periphery of a sperm cell.


type I pilus

description: A short filamentous structure on the surface of a bacterial cell distinguished from other pili by their D-mannose-sensitive agglutinatination of erythrocytes. In E. coli, type I pili consist of a short tip fibrillum made up of the adhesin protein (FimH) and two minor subunits (FimG and FimF) that is joined to the pilus rod, a homopolymer of ~1000 FimA subunits.


amyloplast membrane

description: Either of the lipid bilayers that surround an amyloplast and form the amyloplast envelope.


polytene chromosome weak point

description: A region of the polytene chromosome where the diameter is considerably decreased, probably resulting from local differences in chromosome organization.


cyanelle stroma

description: The space enclosed by the double membrane of a cyanelle.


chloroplast membrane

description: Either of the lipid bilayers that surround a chloroplast and form the chloroplast envelope.


cluster of actin-based cell projections

description: A cell part consisting of multiple, closely packed actin-based cell projections.


proplastid stroma

description: The space enclosed by the double membrane of a proplastid.


ciliary shaft

description: The mid part of a cilium between the ciliary base and ciliary tip that extends into the extracellular space.


intracellular immature spore

description: A cell or part of the cell that constitutes an early developmental stage of a spore, a small reproductive body that is highly resistant to desiccation and heat and is capable of growing into a new organism, produced especially by certain bacteria, fungi, algae, and nonflowering plants.


rhoptry

description: A large, club-shaped secretory organelle that forms part of the apical complex of an apicomplexan parasite, and consists of a bulbous body and a narrow electron-dense neck that extends through the conoid at the apical tip of the parasite. The rhoptry necks serve as ducts through which the contents of the rhoptries are secreted after attachment to the host has been completed and at the commencement of invasion. Rhoptry proteins function in the biogenesis and host organellar association of the parasitophorous vacuole.


cortical endoplasmic reticulum lumen

description: The volume enclosed by the membranes of the cortical endoplasmic reticulum.


gerontoplast stroma

description: Any plastid stroma that is part of a gerontoplast.


spindle pole body

description: The microtubule organizing center in fungi; functionally homologous to the animal cell centrosome.


pilus tip

description: The pointed extremity furthest from the cell of a pilus.


subpellicular network

description: A mechanically stable cytoskeletal structure associated with the cytoplasmic face of the pellicle and surrounding the microtubule-based cytoskeleton.


hydrogenosome lumen

description: The volume enclosed by the hydrogenosome membrane.


intermediate layer of spindle pole body

description: Structure between the central and outer plaques of the spindle pole body.


primary cell wall

description: A plant cell wall that is still able to expand, permitting cell growth. Primary cell walls contain more pectin than secondary walls and no lignin is present.


S-layer

description: A crystalline protein layer surrounding some bacteria.


half bridge of spindle pole body

description: Structure adjacent to the plaques of the spindle pole body.


glycoprotein network

description: An extracellular matrix part that consists of cross-linked glycoproteins.


acidocalcisome

description: An electron-dense acidic membrane-bounded organelle which contains a matrix of pyrophosphate and polyphosphates with bound calcium and other cations.


endoplasmic reticulum cisternal network

description: A subcompartment of the endoplasmic reticulum consisting of flattened, disc-shaped domains known as cisternae. These are typically found close to the nucleus and are generally more prominent in secretory cells.


host cell junction

description: A plasma membrane part that forms a specialized region of connection between two host cells or between a host cell and the host extracellular matrix. At a host cell junction, anchoring proteins extend through the host plasma membrane to link cytoskeletal proteins in one cell to cytoskeletal proteins in neighboring cells or to proteins in the extracellular matrix.


outer plaque of spindle pole body

description: One of three laminate structures that form the spindle pole body; the outer plaque is in the cytoplasm.


plastid membrane

description: Either of the lipid bilayers that surround a plastid and form the plastid envelope.


host cell late endosome membrane

description: The lipid bilayer surrounding a host cell late endosome.


chloroplast starch grain

description: Plant storage body for amylose and amylopectin, 1-100um in diameter, and located in chloroplasts. Also contains small amounts of enzymes, amino acids, lipids and nucleic acids. The shape of the grain varies widely amongst species, but is often spherical or disk-shaped.


endexine

description: The inner part of the exine, which stains.


acroblast

description: A cone-shaped structure in the head of a spermatozoon, which is formed by the coalescence of Golgi fragments following the completion of meiosis. The acroblast is situated adjacent to the acrosomal vesicle.


haustorium

description: A projection from a cell or tissue that penetrates the host's cell wall and invaginates the host cell membrane.


organelle

description: Organized structure of distinctive morphology and function. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton, and prokaryotic structures such as anammoxosomes and pirellulosomes. Excludes the plasma membrane.


name: inner plaque of mitotic spindle pole body

description: One of three laminate structures that form the mitotic spindle pole body; the inner plaque is in the nucleus.


extraorganismal space

description: The environmental space outside of an organism; this may be a host organism in the case of parasitic and symbiotic organisms.


cofilin-actin rod

description: A cellular structure consisting of parallel, hexagonally arranged actin tubules, comprising filamentous actin and disulfide cross-linked cofilin multimers.


pectic matrix

description: The gel-like pectin matrix consists of the interlinked acidic and neutral pectin networks that are further cross-linked by calcium bridges. Pectins consist largely of long chains of mostly galacturonic acid units (typically 1,4 linkages and sometimes methyl esters). Three major pectic polysaccharides (homogalacturonan, rhamnogalacturonan I and rhamnogalacturonan II) are thought to occur in all primary cell walls.


bounding membrane of organelle

description: The lipid bilayer that forms the outer-most layer of an organelle.


acidocalcisome membrane

description: The lipid bilayer surrounding an acidocalcisome.