AP BIOLOGY

Detailed explanation-1: -Essentially, the phrase is saying, “Enjoy the pain! Suffer through your workout! Keep going even if it hurts!” A healthy fitness regimen should not be framed negatively. Exercise should be enjoyable, not something you feel like you have to do.

Detailed explanation-2: -4: Lactic acid fermentation makes ATP in the absence of oxygen by converting glucose to lactic acid (through a pyruvate intermediate). Making lactic acid from pyruvate oxidizes NADH, regenerating NAD+ so that glycolysis can continue to make more ATP rapidly.

Detailed explanation-3: -This burning sensation is associated with a buildup of acid in the muscles during intense exercise, and lactic acid has long been thought to be the culprit in that acid buildup, known as acidosis. Lactic acid is a byproduct of anaerobic metabolism, in which the body produces energy without using oxygen.

Detailed explanation-4: -Lactic acid fermentation has two steps: glycolysis and NADH regeneration. During glycolysis, one glucose molecule is converted to two pyruvate molecules, producing two net ATP and two NADH.