This dehydrogenase, like any dehydrogenase, will essentially catalyze the movement, the transfer of a Hydride group from one molecule to another. In this case it's from this NADH onto this pyruvate molecule. And so ultimately what happens is the Hydride from this essentially goes on, attacks this carbon and then the H is picked up by the oxygen and so we form this lactate. Now if an H is picked up by this, that is what we call lactic acid. So lactate is the conjugate base of lactic acid. So we see that the lactate dehydrogenase catalyze the transfer of the hydrad group and so ultimately we regenerate that NAD plus.