AP BIOLOGY

Detailed explanation-1: -You may have not been aware that your muscle cells can ferment. Fermentation is the process of producing ATP in the absence of oxygen, through glycolysis alone. Recall that glycolysis breaks a glucose molecule into two pyruvate molecules, producing a net gain of two ATP and two NADH molecules.

Detailed explanation-2: -The muscle cells convert glucose to pyruvic acid. An enzyme in the muscle cells then converts the pyruvic acid to lactic acid. As in the yeast, this reaction frees up the NAD while providing the cells with two ATP molecules from glycolysis.

Detailed explanation-3: -Humans undergo lactic acid fermentation when the body needs a lot of energy in a hurry. When you are sprinting full speed, your cells will only have enough ATP stored in them to last a few seconds. Once the stored ATP is used, your muscles will start producing ATP through lactic acid fermentation.

Detailed explanation-4: -Although fermentation produces less ATP, it has the advantage of doing so very quickly. It allows your muscles, for example, to get the energy they need for short bursts of intense activity. Aerobic cellular respiration, in contrast, produces ATP more slowly.

Detailed explanation-5: -Our muscle cells can undergo this process when they are in oxygen debt. If enough oxygen is not present to undergo aerobic respiration, pyruvate will undergo lactic acid fermentation.