tartrate(in) + citrate(out) <=> tartrate(out) + citrate(in)
tartrate(in) + citrate(out) <=> tartrate(out) + citrate(in)
tartrate(in) + citrate(out) <=> tartrate(out) + citrate(in)
tartrate(in) + citrate(out) <=> tartrate(out) + citrate(in)