Enzyme catalysis photosynthesis

First assumptions as to the possibility of hydrogen changing its position in the process of transformation of one chemical particle into another one were voiced nearly 200 years ago [31], and the mechanism of this enormously important reaction has been attracting attention ever since. The reason for this interest is obvious seeing that the proton transfer reactions underlie the acid-base equilibria and determine the mechanisms of a broad range of biological phenomena such as the transport across membranes, enzymic catalysis, photosynthesis, the formation of the ATP acid, spontaneous mutations etc. 

Macromolecular crystallography is a very powerful method used to study complex biological systems. The structures of a wide variety of proteins, nucleic acids and their assemblies have been determined at atomic or near-atomic resolution. As a result, a detailed understanding has been gained of various living processes such as enzyme catalysis, the immune response, the encoding of hereditary information, viral infection and photosynthesis. 

Cobalt B Enzymes Coenzymes Cytochrome Oxidase Iron Heme Proteins Electron Transport Iron Proteins with Dinuclear Active Sites Iron Proteins with Mononuclear Active Sites Iron-Sulfur Models of Protein Active Sites Metallocenter Biosynthesis Assembly. Metalloregulation Molybdenum MPT-containing Enzymes Nickel Enzymes Cofactors Nitrogenase Catalysis Assembly Photosynthesis Tungsten Proteins Vanadium in Biology Zinc DNA-binding Proteins. 

The ambient concentration of CO2 in seawater ( 10 pM) is low compared to the half saturation constant of RubisCO (ribulose 1,5-bisphosphate carboxylase/oxygenase) the enzyme that fixes the inorganic carbon into PG3 (3-phos-phoglycerate) in the first step of the Calvin cycle (the dark reaction of photosynthesis). Microalgae have thus evolved various carbon concentrating mechanisms (CCM) to augment the CO2 concentration at the site of fixation [55]. These mechanisms all involve interconversion between CO2 and HCOJ at some point. But at neutral pH the hydration/dehydration reaction of CO2/ HCOj" has a half life of 30 s, much too slow for a cellular process (for example, diffusion from one end of the cell to the other takes on the order of 10 ms), and requires catalysis. The enzyme CA is an extraordinary effective catalyst some CA catalyze the CO2/HCO3 reaction at a rate that nearly reaches the limit imposed by the diffusion of molecules [56]. 

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