Anaerobic respiration is a type of respiration that takes place in the absence of oxygen and aerobic respiration. The steps of anaerobic respiration have some similarities to aerobic respiration. Both forms start their process with glycolysis, which is the beginning of carbohydrate catabolism, or the breakdown of larger molecules into smaller ones.
The first step in any version of cellular respiration is glycolysis. Glycolysis is the stage where glucose is broken down into pyruvate, and it also produces the first two molecules of adenosine triphosphate. In anaerobic respiration, the pyruvate is used in the process of fermentation, which creates ethanol and nicotinamide adenine dinucleotide, or NAD+. NAD+ is very important in cellular respiration because it is required by glycolysis to function. Without glycolysis, the cells would die instead of continuing to create energy.
Anaerobic respiration takes place in the cytoplasm, the fluid part. This type of respiration leaves behind large amounts of energy in the lactate molecules or the ethanol. This energy is unusable and must be gotten rid of as waste. One example of the importance of anaerobic respiration is exercise. When a person's muscles are pushed hard enough, the muscles use up all the oxygen built in them and the cells then move onto anaerobic respiration so that the muscles can burn lactic acid to keep moving and working.