(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)