Lactic Acid Fermentation is a biological process where glucose is converted into energy in the absence of oxygen. This process occurs in certain bacteria and animal cells, such as muscle cells during intense exercise. The end product of this fermentation is lactic acid, which can accumulate and cause muscle fatigue. In addition to its role in muscles, lactic acid fermentation is also used in food production. It is responsible for the sour taste in products like yogurt and sauerkraut. The bacteria involved, such as Lactobacillus, help preserve food and enhance its nutritional value.