In enzymology, a D-lactate dehydrogenase is an enzyme that catalyzes the chemical reaction -lactate + 2 ferricytochrome c-553 ⇌ {\displaystyle \rightleftharpoons } pyruvate + 2 ferrocytochrome c-553Thus, the two substrates of this enzyme are -lactate and ferricytochrome c-553, whereas its two products are pyruvate and ferrocytochrome c-553. Wikipedia