Final answer:
Anaerobic respiration, or fermentation, is a process that involves only glycolysis, using an organic molecule as the final electron acceptor, and does not utilize the TCA or ETC. It produces a minimal amount of ATP, with just two ATP molecules produced per glucose molecule during glycolysis.
Step-by-step explanation:
Anaerobic cellular respiration, also known as fermentation, is a type of cellular respiration that does not require oxygen. It involves glycolysis, but it does not utilize the citric acid cycle (TCA) or an electron transport system (ETC). The final electron acceptor in fermentation is an organic molecule, not an inorganic molecule as used in aerobic respiration.
Fermentation has the primary goal of regenerating NAD+ from NADH, which allows glycolysis to continue producing ATP. During glycolysis, a small amount of ATP is produced through the process of substrate-level phosphorylation. This is the only stage in fermentation where ATP is directly created, resulting in a yield of approximately two ATP molecules per glucose molecule. In contrast to aerobic respiration, no additional ATP is produced in fermentation beyond this stage because it does not involve an ETC or oxidative phosphorylation.
Anaerobic respiration is critically important in environments lacking oxygen and is employed by various organisms, including bacteria, yeasts, and human muscle cells under certain conditions. Many industrial processes, such as the production of yogurt, bread, wine, and biofuels, rely on fermentation.