What major product distinguishes anaerobic respiration from aerobic respiration?

The major product that distinguishes anaerobic respiration from aerobic respiration is lactic acid or ethanol. During anaerobic respiration, organisms convert glucose into energy without the presence of oxygen, leading to the production of either lactic acid (in animals and some bacteria) or ethanol and carbon dioxide (in yeast).

In contrast, aerobic respiration occurs in the presence of oxygen and fully breaks down glucose into carbon dioxide and water, producing a higher yield of ATP in the process. The formation of lactic acid or ethanol is a crucial indicator of anaerobic conditions, as these byproducts signify that the organism is relying on less efficient energy production methods due to limited oxygen availability. This understanding is essential in differentiating metabolic pathways within various organisms based on their energy requirements and environmental conditions.