Lactic acid fermentation is a biological process through which glucose (or other sugars) is converted into lactic acid, primarily by certain bacteria and in muscle cells of animals under anaerobic conditions (low or no oxygen). The overall chemical reaction for lactic acid fermentation can be summarized as follows:
\[ \text{C}6\text{H}{12}\text{O}_6 \rightarrow 2 \text{C}_3\text{H}_6\text{O}_3 \]
In this equation, one molecule of glucose (C₆H₁₂O₆) is converted into two molecules of lactic acid (C₃H₆O₃). This process also produces a small amount of energy in the form of ATP (adenosine triphosphate) during the breakdown of glucose.