glycine(out) + n H(+)(in) <=> glycine(in) + n H(+)(out)
glycine(out) + n h(+)(in) <=> glycine(in) + n h(+)(out)
glycine(out) + n H(+)(in) <=> glycine(in) + n H(+)(out)
glycine(out) + n h(+)(in) <=> glycine(in) + n h(+)(out)