Which statement best explains why fermentation occurs in mammals? It enables mammals to generate additional ATPATP in an oxygen‑rich environment. It breaks down lactic acid to generate a small amount of ATPATP under anaerobic conditions. It generates ethanol, which can be used as an alternative source of energy. It produces an acid that maintains blood pH within a narrow range. It allows glycolysis to continue under anaerobic conditions by replenishing NAD+NAD+ .

In the presence of oxygen, glycolysis, Kreb's cycle and oxidative phosphorylation happen to provide about 32 ATP molecules. In its absence, only glycolysis can take place because it's the only step that doesnt need oxygen, to give a net supply of 2 ATP.

Even though glycolysis doesn't need oxygen, it needs NAD, and if the reduced NAD doesn't lose its hydrogens via oxidative phosphorylation, pyruvate (the end product of glycolysis) becomes the recipient of the hydrogen.

Pyruvate gets reduced to lactate.

Oseni Oseni · Answer 2 · 2021-09-30T14:18:42+02:00

The correct answer as to which best explains why fermentation occurs in mammals would be that it breaks down lactic acid to generate a small amount of ATP under anaerobic condition.

Aerobic respiration takes place in 3 steps:

Glycolysis: during which glucose is converted into pyruvate molecules with 2 ATP and 2NADH molecules produced.
Citric acid cycle: during which pyruvate molecules from glycolysis are converted to CO2 with ATP, NADH, and FADH2 generated
Electron transport chain: during which the NADH and FADH2 produced in citric acid cycle are used to generate ATP.

When oxygen becomes inadequate during rigorous activities in human cells, pyruvate molecules cannot proceed to the citric acid cycle due to lack of oxygen. Instead, the pyruvate molecules are converted to lactic acid through fermentation to generate 2 molecules of ATP.

More on lactic acid fermentation can be found here: https://brainly.com/question/2095032