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Obtaining energy

Anaerobic respiration

Anaerobic respiration is a type of respiration that does not use oxygen. It is used when there is not enough oxygen for aerobic respiration. It can be summarised by the following equation:

glucose → lactic acid (+ energy released)

This type of respiration may be used when, for example, an animal is being chased by a predator.

Anaerobic respiration also takes place in plants and some microbial cells in the presence of little or no oxygen. Examples of this include the roots of plants in waterlogged soils and bacteria in puncture wounds.

Anaerobic respiration in plant cells and some microorganisms (such as yeast) produces ethanol and carbon dioxide, as opposed to lactic acid. It can be summarised by the following equation:

glucose → ethanol + carbon dioxide (+ energy released)

Aerobic respiration releases more energy per glucose molecule than anaerobic respiration.

Back to The processes of life index

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