Lactate, Lactic Acid and Acidosis
With respect to exercise, what do you think of when I say, “Lactic Acid?” Legs burning? Acidosis? Horrible stuff that slows me down? Lactic acid and lactate typically get a bad rap from athletes, but what if I said that rather than slowing you down, lactate production enables high-intensity exercise? Well, it does. Lactate vs. Lactic Acid First, let’s discuss the compound itself. Lactate is not lactic acid. Lactate is a carboxylate, whereas lactic acid is a carboxylic acid. This means the carboxyl group of the lactate molecule is deprotonated and cannot contribute further to acidosis. The image below shows the difference between the two molecule types. The reason lactate does not exist as it's protonated acid form in the body is because the pKa of lactate is a low 3.9. This means is that in a solution with a pH higher than 3.9, the compound will exist as the deprotonated carboxylate, lactate. As shown below, in Table I from Cairns ( 2006 ), the