ADP(out) + diphosphate(in) <=> ADP(in) + diphosphate(out)
adp(out) + diphosphate(in) <=> adp(in) + diphosphate(out)
ADP(out) + diphosphate(in) <=> ADP(in) + diphosphate(out)
adp(out) + diphosphate(in) <=> adp(in) + diphosphate(out)