Final answer:
Fermentation is a biological process that converts carbohydrates to alcohol or organic acids anaerobically. This process is essential for the production of various foods and pharmaceuticals, with common end products being ethanol or lactic acid.
Step-by-step explanation:
An essential feature of every fermentation process is the conversion of carbohydrates, such as sugars, to alcohol or organic acids under anaerobic conditions (in the absence of oxygen). During this biochemical process, organisms such as yeast or bacteria metabolize the sugars, and the pyruvate produced by glycolysis does not enter the citric acid cycle. Instead, it is used to accept electrons from NADH, regenerating NAD+ and allowing glycolysis to continue. The process leads to the production of fermentation end products like ethanol or lactic acid, which have significant commercial value in industries producing items such as wine, beer, bread, cheese, and various pharmaceutical products.