(R)-glycerate(in) + H(+)(in) <=> (R)-glycerate(out) + H(+)(out)
(r)-glycerate(in) + h(+)(in) <=> (r)-glycerate(out) + h(+)(out)
(R)-glycerate(in) + H(+)(in) <=> (R)-glycerate(out) + H(+)(out)
(r)-glycerate(in) + h(+)(in) <=> (r)-glycerate(out) + h(+)(out)