Anaerobic Respiration Fermentation

Anaerobic Respiration

Anaerobic respiration is a process in which cells obtain energy from the breakdown of organic compounds in the absence of oxygen. This process is used by many organisms, including bacteria, yeast, and some plants, to generate energy when oxygen is not available.

Anaerobic respiration is less efficient than aerobic respiration, which is the process of obtaining energy from the breakdown of organic compounds in the presence of oxygen. This is because anaerobic respiration does not produce as much energy as aerobic respiration. However, anaerobic respiration is still a valuable process for organisms that live in environments where oxygen is not available.

There are two main types of anaerobic respiration:

Lactic acid fermentation: This type of anaerobic respiration produces lactic acid as a byproduct. Lactic acid fermentation is used by bacteria to produce yogurt, cheese, and other fermented foods.

aerobic respiration

Alcoholic fermentation: This type of anaerobic respiration produces ethanol (alcohol) and carbon dioxide as byproducts. Alcoholic fermentation is used by yeast to produce wine, beer, and other alcoholic beverages.

ATP Production in Aerobic vs. Anaerobic Respiration

Aerobic respiration and anaerobic respiration are two different ways that cells generate energy from food. Aerobic respiration is more efficient and produces more ATP, while anaerobic respiration is less efficient but can occur in the absence of oxygen.


Aerobic Respiration

Anaerobic Respiration


More efficient

Less efficient

ATP production

36-38 ATP per glucose molecule

2 ATP per glucose molecule

Oxygen requirement

Requires oxygen

Does not require oxygen


Carbon dioxide and water

Lactic acid or ethanol

Examples of organisms that use it

Humans, animals, plants

Bacteria, yeast, some plants