an N-acyl-sphingoid base + D-galactose => a D-galactosylceramide + H2O
an n-acyl-sphingoid base + d-galactose => a d-galactosylceramide + h2o
an N-acyl-sphingoid base + D-galactose => a D-galactosylceramide + H2O
an n-acyl-sphingoid base + d-galactose => a d-galactosylceramide + h2o