Final answer:
If you're a heterotroph and don't have oxygen for cellular respiration, you can use fermentation as a process to produce ATP without oxygen. Fermentation involves the addendum to glycolysis, allowing glycolysis to proceed and recycle NADH back into NAD+.
Step-by-step explanation:
If you're a heterotroph and don't have oxygen for cellular respiration, you can use fermentation as a process to produce ATP without oxygen. Fermentation involves the addendum to glycolysis, the first stage of cellular respiration. It allows glycolysis to proceed and recycle NADH back into NAD+ by using pyruvate to accept electrons, without going through the Krebs cycle or oxidative phosphorylation.
Fermentation is extremely important in various human activities such as the production of alcoholic beverages and desirable food products like sour-dough, sauerkraut, sour cream, and yogurt. Some fermenting organisms can live with or without oxygen, while others carry out fermentation regardless of oxygen availability.