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The LH 2 is usually bound to photosystem II, but it can undock and bind PS I instead depending on light conditions. [4] This behavior is controlled by reversible phosphorylation. This reaction represents a system for balancing the excitation energy between the two photosystems.
The photosynthetic efficiency (i.e. oxygenic photosynthesis efficiency) is the fraction of light energy converted into chemical energy during photosynthesis in green plants and algae. Photosynthesis can be described by the simplified chemical reaction 6 H 2 O + 6 CO 2 + energy → C 6 H 12 O 6 + 6 O 2
The intermediate molecule at (3) is 3-keto-2-carboxyarabinitol-1,5-bisphosphate, which decays almost instantaneously into 3-phosphoglycerate. The large fractionation of 13 C in photosynthesis is due to the carboxylation reaction, which is carried out by the enzyme ribulose-1,5-bisphosphate carboxylase oxygenase, or RuBisCO . [ 5 ]
Reaction centers are present in all green plants, algae, and many bacteria.A variety in light-harvesting complexes exist across the photosynthetic species. Green plants and algae have two different types of reaction centers that are part of larger supercomplexes known as P700 in Photosystem I and P680 in Photosystem II.
A cell during anaphase. Microtubules are visible in green. Stages of late M phase in a vertebrate cell. Anaphase (from Ancient Greek ἀνα-() ' back, backward ' and φάσις (phásis) ' appearance ') is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell.
Photons trapped by photosystem II move the system from state S 0 to S 1 to S 2 to S 3 and finally to S 4. S 4 reacts with water producing free oxygen: 2 H 2 O → O 2 + 4 H + + 4 e −. This conversion resets the catalyst to the S 0 state. The active site of the OEC consists of a cluster of manganese and calcium with the formula Mn 4 Ca 1 O x ...
Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.
When CO 2 concentration is high and O 2 concentration is low photorespiration is suppressed and C 3 assimilation is fast and efficient, with ATP/GA approaching the theoretical minimum of 3. In C 4 photosynthesis CO 2 concentration at the RuBisCO carboxylating sites is mainly the result of the operation of the CO 2 concentrating mechanisms ...