Search results
Results from the WOW.Com Content Network
In cyclic photophosphorylation, the high-energy electron released from P700, a pigment in a complex called photosystem I, flows in a cyclic pathway. The electron starts in photosystem I, passes from the primary electron acceptor to ferredoxin and then to plastoquinone , next to cytochrome b 6 f (a similar complex to that found in mitochondria ...
Cyclic phosphorylation is important to create ATP and maintain NADPH in the right proportion for the light-independent reactions. The net-reaction of all light-dependent reactions in oxygenic photosynthesis is: 2 H 2 O + 2 NADP + + 3ADP + 3P i → O 2 + 2 H + + 2NADPH + 3ATP. PSI and PSII are light-harvesting complexes.
Alarm photosynthesis represents a photosynthetic variant to be added to the well-known C4 and CAM pathways. However, alarm photosynthesis, in contrast to these pathways, operates as a biochemical pump that collects carbon from the organ interior (or from the soil) and not from the atmosphere. [35] [36]
The number of these pigment molecules varies from organism to organism. For instance, the cyanobacterium Synechococcus elongatus ( Thermosynechococcus elongatus ) has about 100 chlorophylls and 20 carotenoids, whereas spinach chloroplasts have around 200 chlorophylls and 50 carotenoids.
The enzymes in the Calvin cycle are functionally equivalent to most enzymes used in other metabolic pathways such as gluconeogenesis and the pentose phosphate pathway, but the enzymes in the Calvin cycle are found in the chloroplast stroma instead of the cell cytosol, separating the reactions. They are activated in the light (which is why the ...
Because of this, P680 + is highly oxidizing and can take part in the splitting of water. [2] Photosystem II (of cyanobacteria and green plants) is composed of around 20 subunits (depending on the organism) as well as other accessory, light-harvesting proteins.
Biological organization spans several scales and are determined based different structures depending on what the system is. [1] Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the ...
C 4 carbon fixation or the Hatch–Slack pathway is one of three known photosynthetic processes of carbon fixation in plants. It owes the names to the 1960s discovery by Marshall Davidson Hatch and Charles Roger Slack. [1] C 4 fixation is an addition to the ancestral and more common C 3 carbon fixation.