Difference between revisions of "Photorespiration"

Latest revision as of 09:29, 11 September 2021

high-resolution terminology - matching measurements at high-resolution

Photorespiration

Description

Photorespiration is the process by which the enzyme RuBisCo oxygenates ribulose biphosphate (RuBP) instead of carboxylating it as part of the Calvin-Benson cycle, creating phosphoglycolate, a product that cannot be used within this cycle, thus dissipating the energy in photosynthesis. It is estimated that approximately 25 % of RuBisCo reactions are photorespiration, meaning a potential 25 % reduction in photosynthetic output due to the carbon fixed by photorespiration being released as carbon dioxide and nitrogen as ammonia, while the other product, 3-phosphoglycerate (G3P), requires a higher metabolic cost. This process involves a complex network of enzymes and metabolite exchanges between the chloroplasts, peroxisomes and mitochondria. It is also known as the oxidative photosynthetic carbon cycle or C₂ photosynthesis. Environmental conditions tend to affect it, such as temperature and partial pressure of oxygen and carbon dioxide. C₄ plants, CAM plants and algae have biochemical and biophysical mechanisms to overcome the photosynthetic losses due to photorespiration making them more photosynthetically efficient than C₃ plants. Recent plant biotechnology advances focuse on increasing plant photosynthetic carbon fixation by reducing photorespiration loses.

Reference:

Stern K (2003) Introductory plant biology. McGraw-Hill, New York. ISBN 978-0-07-290941-8.

Simplified photorespiration diagram

Bioblast links: PhotoBiology and plant physiology - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>

PhotoBiology: photosynthesis

» PhotoBiology

» Photosynthesis

Plant physiology: respiration

» Photorespiration

» Chlororespiration

» Light-enhanced dark respiration

NextGen-O2k and PB-Module

» NextGen-O2k

» PB-Module

» PB-Sensor

@@ Line 1: / Line 1: @@
 {{MitoPedia
-|abbr=
+|description='''Photorespiration''' is the process by which the enzyme RuBisCo oxygenates ribulose biphosphate (RuBP) instead of carboxylating it as part of the Calvin-Benson cycle, creating phosphoglycolate, a product that cannot be used within this cycle, thus dissipating the energy in [[photosynthesis]]. It is estimated that approximately 25 % of RuBisCo reactions are photorespiration, meaning a potential 25 % reduction in photosynthetic output due to the carbon fixed by photorespiration being released as carbon dioxide and nitrogen as ammonia, while the other product, 3-phosphoglycerate (G3P), requires a higher metabolic cost. This process involves a complex network of enzymes and metabolite exchanges between the chloroplasts, peroxisomes and mitochondria. It is also known as the oxidative photosynthetic carbon cycle or C<sub>2</sub> photosynthesis. Environmental conditions tend to affect it, such as temperature and partial pressure of oxygen and carbon dioxide. C<sub>4</sub> plants, CAM plants and algae have biochemical and biophysical mechanisms to overcome the photosynthetic losses due to photorespiration making them more photosynthetically efficient than C<sub>3</sub> plants. [https://www.biotechniques.com/molecular-biology/new-photorespiratory-pathways-the-key-to-humanitys-survival/ Recent plant biotechnology advances] focuse on increasing plant photosynthetic carbon fixation by reducing photorespiration loses.
-|description='''Photorespiration''' is the process by which the enzyme RuBisCo oxygenates the Ribulose Biphosphate (RuBP) instead of carboxylating it as part of the Calvin-Benson cycle, wasting as a consequence the energy produced by [[https://wiki.oroboros.at/index.php/Photosynthesis photosynthesis]] (in the form of a direct cost in ATP and NAD(P)H) and creating a product that cannot be used within this cycle, the phosphoglycolate. It is estimated that approximately 25% of the reactions done by the RuBisCo are by photorespiration which means a potentially 25% reduction of the photosynthetic output, because the carbon fixed by photorespiration is released in the form of carbon dioxide and nitrogen as ammonia and the other product of the RuBP oxygenation, the 3-phosphoglycerate (G3P), requires a higher metabolic cost. This process involves a complex network of enzymes and metabolites exchanges between the chloroplasts, peroxisomes and mitochondria. It is also known as the oxidative photosynthetic carbon cycle or C<sub>2</sub> photosynthesis and abiotic conditions tend to affect it such as the atmospheric partial pressures of oxygen and carbon dioxide or temperature. Certain type of plants (C<sub>4</sub> plants and CAM plants) and algae have biochemical and biophysical mechanisms to overcome the photosynthesis loses due to photorespiration making them more photosynthetically efficient than the C<sub>3</sub> plants.
+|info=:::: Stern K (2003) Introductory plant biology. McGraw-Hill, New York. ISBN 978-0-07-290941-8.
-|info=::::
 }}
+[[File:photorespiration.png|centre|400px]]
+:::::::::::::::::::::::'''Simplified photorespiration diagram'''
-Communicated by [[Huete-Ortega M]] 2020-07-29
+{{NextGen-O2k H2020-support}}
-{{NextGen-O2k}}
+{{Template:Keywords: PhotoBiology and plant physiology}}
-{{Labeling
-|additional=MitoPedia:NextGen-O2k
-}}