AP BIOLOGY

Detailed explanation-1: -The correct answer is (B) because humans cannot produce alcohol when they are exercising.

Detailed explanation-2: -To recap, ATP and phosphocreatine are the first energy sources to fuel the muscles during physical activity but are depleted very rapidly (Figure 12). Glucose then follows, degraded by glycolysis and then either fermentation (anaerobic metabolism) or the Krebs cycle/ETC (aerobic metabolism).

Detailed explanation-3: -Since only single-celled organisms such as bacteria and yeast can do alcohol fermentation, human cells are not capable of performing it.

Detailed explanation-4: -The human body uses carbohydrate, fat, and protein in food and from body stores for energy to fuel physical activity. These essential nutrients are needed regardless of the intensity of the activity you are doing.

Detailed explanation-5: -Fermenting microorganisms and their by-products define the fermentation type. There are two main types of fermentation, called lactic acid fermentation and alcoholic fermentation (Figure 1) [2]. Both types of fermentation are essential for many purposes that are useful for humans.