Photosynthesis Calvin-Benson cycle

All the O atoms evolved as Og come from water none comes from carbon dioxide. But 12 O atoms are evolved as 6 Og, and only 6 O atoms appear as 6 HgO in the equation. Also, 6 COg have 12 O atoms, yet there are only 6 O atoms in CgHigOg. How can yon account for these discrepancies Hint Consider the partial reactions of photosynthesis ATP synthesis, NADP reduction, photolysis of water, and the overall reaction for hexose synthesis in the Calvin-Benson cycle.)... 

PGA (phosphoglycerate) A three-carbon molecule formed when carbon dioxide is added to ribulose biphosphate (RuBP) during the dark reaction of photosynthesis (Calvin, or Calvin-Benson Cycle). PGA is converted to PGAL, using ATP and NADPH. 

Plant biomass species that use the Calvin-Benson cycle are called C3 plants. The cycle is common in many fruits, legumes, grains, and vegetables. C3 plants usually exhibit low rates of photosynthesis at light saturation, low light... 

Calvin-Benson cycle The synthesis of carbohydrate from C02, in particular during oxygenic photosynthesis... 

The isotopic fingerprinting of photosynthesis. Photosynthesis is currently an important means of fixing inorganic carbon and is used by plants, algae, bacteria, and Archaea. A particularly important enzyme (catalyst) in this process is Rubisco, the official shortened name for a molecule with a much more intricate systematic name. The reactions which take place in this process operate according to the Calvin-Benson Cycle and lead to isotopic fractionations of up to 30%o. 

Transketolase is also involved in the Calvin-Benson cycle of photosynthesis by plants and some bacteria. 

AH the sugar (CH2O) needs to be formed by photosynthesis in the chloroplast. In the Calvin—Benson—Bassham cycle CO2 is reduced to the level of sugar (CH2O) according to the following reaction and stoichiometry ... 

By combining the Calvin—Benson—Bassham cycle with the fight reactions the following general reaction of photosynthesis is then obtained... 

Fig. 1. Hipothesis of two interacting carboxylation systems in isoprens releasing plant photosynthesis. Designations BC - pool of reactions of Benson-Calvin cycle AcCoA - pool of acetyl-CoA and isoprene biosynthesis RUBPC/O-ribulosebisphsphate C/0 X-C-unknown carboxylase leading to acetyl-CoA biosyynthesis PGA-phosphoglyceric acid PGAL- phosphoglyceric aldehyde GA-D,L-glyceraldehyde a,b,c...n-alternative pathways of acetyl-CoA use.

At high irradiance photosynthesis is limited by CO2 assimilation and more light is absorbed than can be effectively used to drive photosynthesis. Dissipation of surplus excitation energy is essential because excessive excitation leads to the light-induced loss of thylakoid efficiency called photoinhibition. When the rate of carbon assimilation limits the overall rate of photosynthesis the capacity of ATP and NADPH production exceeds that of demand by the Benson-Calvin cycle and photosynthetic control of electron transport would be expected (1, 2). Photosynthetic control... 

Although some plants, such as those called C4 and those known as using Crassulacean acid metabolism (CAM) photosynthesis (i.e., xerophytes) initially capture the carbon dioxide (CO2) differently than the C3 plants do, they too subsequently release it to the Calvin cycle (M. Calvin [1911-1997], professor. University of California, Berkeley, since 1937, Nobel Prize in Chemistry 1961 Bassham, I Benson, A. Calvin, M. [1950]./ Biol. C/iem., 1950,7S5,781). 

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