Anaerobic respiration occurs in the absence of oxygen and is less efficient than aerobic respiration. Unlike aerobic respiration, the end products here are ethyl alcohol as in alcoholic fermentation and lactic acid as in animal cells.

In anaerobic respiration, both lactic acid and alcohol are produced as chemical substances.

Anaerobic respiration is a type of cellular respiration that occurs in the absence of oxygen. It is a less efficient process compared to aerobic respiration, which uses oxygen to break down glucose and produce energy. Anaerobic respiration takes place in some microorganisms, as well as in certain muscle cells when there is a lack of oxygen supply.

- Anaerobic Respiration in Microorganisms:
- Lactic Acid Production: Some microorganisms, such as certain bacteria and fungi, produce lactic acid as a byproduct of anaerobic respiration. This process is called lactic acid fermentation. The breakdown of glucose during lactic acid fermentation produces lactic acid, which can accumulate in the cells and cause muscle fatigue or soreness.
- Alcohol Production: Other microorganisms, such as yeast, undergo a different type of anaerobic respiration known as alcoholic fermentation. During this process, glucose is converted into alcohol (ethanol) and carbon dioxide. This is the process responsible for the fermentation of sugars in the production of alcoholic beverages like beer and wine.

- Anaerobic Respiration in Muscle Cells:
- Lactic Acid Production: When there is a lack of oxygen supply to muscle cells during strenuous exercise, anaerobic respiration occurs. Glucose is broken down into lactic acid, which is released into the surrounding tissues and bloodstream. The accumulation of lactic acid in the muscles leads to muscle fatigue and cramps.

In summary, anaerobic respiration can result in the production of lactic acid or alcohol, depending on the type of microorganism or cell involved in the process. Lactic acid is produced by bacteria, fungi, and muscle cells, while alcohol is produced by yeast and other microorganisms.