Electron transport chain
| Parent |
| Energy metabolism |
| Subordinate |
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Respiratory chain Photosynthetic electron transport |
| Gene Ontology |
|---|
| QuickGO |
An electron transport chain is a biological process in which several electron-transferring molecules interact to transport electrons from a donor to one or more acceptors . As a result, an electrochemical proton gradient ΔP arises across the membrane, which, through chemiosmotic coupling, drives the synthesis of ATP from ADP brought about by the ATP synthase (chemiosmotic coupling). The prerequisite for this is that the components of this process are embedded in a biomembrane .
In nature, the electron transport chain originated in the ancestors of the prokaryotes and probably became part of eukaryotic cells through endosymbiosis . In eukaryotes, the process takes place in the mitochondria . In plants, another electron transport chain is linked to photosynthesis .
Respiratory chain
The respiratory chain is part of the metabolism both in prokaryotes and in the cells of more highly developed organisms (eukaryotes). In eukaryotes it takes place in the mitochondria in the inner mitochondrial membrane, in prokaryotes in the cell membrane. In eukaryotes, the enzyme complexes I to IV and the hydrogen ion ( protons ) or electron carriers ubiquinone (coenzyme Q) and cytochrome c , which are embedded or anchored in the inner mitochondrial membrane, are involved in the reaction . The electrochemical gradient caused by the electron transport chain is used for ATP synthesis ( oxidative phosphorylation ).
Photosynthetic electron transport chain
Photosynthesis takes place in plants, algae and cyanobacteria . The photosynthetic electron transport chain is located in the thylakoid membrane of the chloroplasts . Light-harvesting complexes, plastoquinone , cytochrome b 6 f and plastocyanin are involved in the electron transport chain . The gradient caused by the electron transport chain is used for ATP synthesis ( photophosphorylation ).
literature
- P. Schopfer and A. Brennicke: Plant Physiology. 6th edition. Elsevier, 2005, ISBN 3-8274-1561-6 .