Final answer:
All cells perform anaerobic respiration via fermentation when oxygen is scant or absent, producing ATP and oxidizing NADH to NAD+ to maintain energy production and glycolysis.
Step-by-step explanation:
All cells go through anaerobic respiration when oxygen is limited or absent, and this occurs through a pathway known as fermentation. During this process, pyruvate is converted into lactic acid, which allows the cell to generate additional ATP and ensures that glycolysis can continue by oxidizing NADH back into NAD+. This is crucial for cells like erythrocytes that lack mitochondria and for exercising muscles that require rapid ATP production when oxygen delivery is insufficient.
In addition to lactic acid fermentation, which is common in muscle cells, other organisms engage in fermentation types like alcohol fermentation. Fermentation is essential for the production of various food products and for providing energy to cells when oxygen is not available. Furthermore, certain prokaryotes employ anaerobic cellular respiration using inorganic molecules other than oxygen as the final electron acceptor.