(S)-lactate(in) + citrate(out) => (S)-lactate(out) + citrate(in)
(s)-lactate(in) + citrate(out) => (s)-lactate(out) + citrate(in)
(S)-lactate(in) + citrate(out) => (S)-lactate(out) + citrate(in)
(s)-lactate(in) + citrate(out) => (s)-lactate(out) + citrate(in)