Plant respiration

Article By:

Sharkey, Thomas D. Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan.

Last reviewed:April 2019

DOI:https://doi.org/10.1036/1097-8542.524600

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• Plant respiration, published June 2014:Download PDF Get Adobe Acrobat Reader

The metabolism in plants of organic molecules using enzymes to generate usable energy in the form of adenosine triphosphate (ATP). Plant respiration is an important biochemical process in plants whereby, in most cases, specific substrates are oxidized with a subsequent release of carbon dioxide (CO₂). The adenosine triphosphate (ATP) generated by plant respiration (as well as that generated by photosynthesis) [Fig. 1] is used in plant cells to move things within the cell, to make new molecules needed for growth, and to power active transport (the pumping of ions or other substances across a cell membrane against an osmotic gradient). Most plant respiration is aerobic (that is, it requires the presence of oxygen, and is often termed aerobic or cellular respiration) and involves the oxidation of sugars to carbon dioxide. When oxygen is not present, anaerobic respiration, or fermentation, occurs, allowing some ATP synthesis. Fermentation is much less efficient in harvesting energy from organic molecules than aerobic respiration is, and most plants do not tolerate long periods of anaerobiosis. Plant respiration encompasses several pathways, including glycolysis, the Krebs cycle (also called the citric acid cycle or the tricarboxylic acid cycle), and oxidative electron transport. It occurs in all plant cells and is generally similar to animal respiration, with a few notable exceptions (such as a cyanide-insensitive respiration mechanism lacking in animals). See also: Adenosine triphosphate (ATP); Biological oxidation; Carbohydrate metabolism; Citric acid cycle; Energy metabolism; Enzyme; Oxygen; Plant metabolism; Plant physiology; Respiration

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