Final answer:
Lactic acid fermentation is the process that produces lactic acid and it is used during intense exercise. It is a way for our muscles to generate energy when there is insufficient oxygen supply. The enzyme lactate dehydrogenase is involved in this process.
Step-by-step explanation:
Lactic acid fermentation is the process that produces lactic acid. It is used by certain bacteria, like those found in yogurt, and by our muscle cells during intense exercise. This process is used when there is insufficient oxygen supply for aerobic respiration in the muscles. The enzyme lactate dehydrogenase is involved in the conversion of pyruvic acid to lactic acid.