The method by which muscles deprived of oxygen continue to produce ATP (adenosine triphosphate), but with the loss of 34 ATP molecules for every molecule of glucose processed, and with the release of lactate (lactic acid), which is toxic and must be excreted. The reduced nicotinamide adenine dinucleotide (NAD) produced by glycolysis gives up its hydrogen to reduce pyruvate (pyruvic acid), also produced by glycolysis, to yield lactate. The reaction, catalysed by lactate dehydrogenase, is: C6H12O6 (glucose) ® 2C3H6O3 (lactate). The net loss of ATP causes muscles to tire and the accumulation of lactate causes the pain sometimes associated with extreme exercise.
Subjects: Zoology and Animal Sciences.