Which substance is produced during fermentation in animals and is responsible for muscle fatigue?

Lactate is the substance produced during fermentation in animals, particularly when oxygen levels are low, such as during intense exercise. In the presence of insufficient oxygen, muscle cells switch from aerobic respiration to anaerobic fermentation to generate energy quickly. This process converts glucose into lactate, allowing for continued ATP production, but it also leads to an accumulation of lactate in the muscle tissues.

The build-up of lactate is associated with muscle fatigue, as it can interfere with muscle contraction and lead to a decrease in pH within the muscles. This change can inhibit further muscular function and trigger the sensation of fatigue. Understanding this process helps explain why during prolonged or vigorous activity, the body can experience fatigue due to the reliance on anaerobic pathways, resulting in lactate accumulation.

The other substances listed, such as acetate, pyruvate, and adenosine triphosphate, play different roles in the cellular metabolic processes, but they are not specifically linked to the fatigue experienced during anaerobic fermentation in muscles.