AP BIOLOGY

Detailed explanation-1: -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-2: -Muscle cells can continue to produce ATP when oxygen runs low using lactic acid fermentation. However, this often results in muscle fatigue and pain.

Detailed explanation-3: -When animals exercise with a lack of oxygen their muscles can form Lactic acid.

Detailed explanation-4: -Anaerobic Respiration in Animals In animals, anaerobic respiration produces lactic acid as the glucose is not fully broken down. If the lactic acid builds up it can stop the muscles from working, causing cramp.