What is anaerobic respiration in cells?

Anaerobic respiration is a process where cells produce energy without the use of oxygen.

In more detail, anaerobic respiration is a type of cellular respiration that occurs when oxygen is absent or scarce. Cells need to produce energy to function, and they typically do this through aerobic respiration, which requires oxygen. However, in conditions where oxygen is not available, cells can switch to anaerobic respiration.

The process begins in the cytoplasm of the cell, where glucose is broken down into two molecules of pyruvate in a process called glycolysis. This process produces a small amount of energy and does not require oxygen. In aerobic respiration, the pyruvate would then be transported into the mitochondria to be further broken down, producing a large amount of energy. However, in anaerobic respiration, the pyruvate is converted into a different substance in the cytoplasm.

In animal cells and some types of bacteria, the pyruvate is converted into lactate (lactic acid). This process is called lactic acid fermentation. In yeast and some other types of bacteria, the pyruvate is converted into ethanol and carbon dioxide in a process called alcoholic fermentation. Both of these processes produce a small amount of additional energy.

While anaerobic respiration allows cells to produce energy without oxygen, it is much less efficient than aerobic respiration. For each molecule of glucose, anaerobic respiration produces just two molecules of ATP (the cell's energy currency), while aerobic respiration can produce up to 38 molecules of ATP. However, anaerobic respiration can be a lifesaver for cells in oxygen-poor environments, allowing them to continue functioning until oxygen becomes available again.