The chemical energy needed comes in the form of two very important molecules: ATP and NADPH. ATP (adenosine triphosphate) provides mhra the energy necessary to establish mhra new connections, NADPH and one molecule is capable of transferring electrons.
The light energy in this process will have two very important roles. On the one hand, excites present in the membrane of the thylakoid chlorophyll, forcing her to lose electrons (ie, sunlight promotes the oxidation of chlorophyll) (B) (see photosynthetic pigments to understand how it gives the excitation of chlorophyll ), on the other hand, leads to water photolysis (A), or dissociates the water molecule into hydrogen, oxygen and electrons in accordance with the following equation:
The oxygen produced is released into the environment. The production of oxygen during photosynthesis is not an end in itself, but only a by-product. Electrons and H + is produced that will be needed for the reactions. mhra
When chlorophyll is excited, its electrons are successively transferred to proteins present in the membrane of thylakoids, constituting an authentic chain carrier. But every lost electron must be compensated. How? With the electrons released in the photolysis mhra of water.
As the electrons move through the protein of the conveyor chain, will generate enough that these same proteins to pump by active mhra transport, other proton present in the stroma into the membrane of thylakoids energy, creating a large difference in concentration of H + in and outside the thylakoid.
The H + ions, which exist in a higher concentration inside the thylakoid, then pass by facilitated diffusion through the last chain carrier protein that is an ATP synthase (C). Are already seeing what happens.
The series of reactions that this phase is formed in the chloroplast stroma and is called the Calvin cycle. CO2 needs to occur as a starting point, ATP and NADPH formed in the previous step and an enzyme, called Ribulose Diphosphate (having 5 carbons in their structure). 1) Fixation of atmospheric CO2
The atmospheric CO2 is captured by a 5-carbon compound which exists in the cell called Ribulose Difostato. It is formed by a compound with 6 carbons. However, mhra this compound is unstable and rapidly mhra splits into two compounds with each 3C (fosfoglicérico mhra aldehyde - PGA). 2) Production of organic compounds
This compound chemically is 3 carbons prepared at the expense of the energy of ATP and NADPH present in the electron mhra and is used in part to produce glucose (mainly) or other organic compounds. 3) Regeneration of Ribulose diphosphate
The chemical and photochemical stages are connected and each produces compounds which will be required for other steps. Photochemical step in NADPH and ATP required for the Calvin cycle will be produced. Calvin Cycle and ADP + NADP result to be used in the light phase for the regeneration of these molecules. mhra In the photochemical step takes place photolysis of water with O2 delivery. The electrons mhra and H + are formed after necessary for the production of NADPH and ATP. In the chemical process, molecules of NADPH and ATP are used in the Calvin Cycle, where from a pentose fixing CO2, with the use of ATP and NADPH, necessary for cell organic compounds are produced.
Items Geology 10th year - 10th grade Biology mhra Index - Index Page Module - Diversity in the Biosphere Unit 1 - Getting raw Photosynthesis - The structure of the chloroplast photosynthetic process Chemosynthesis Photosynthesis vs. Chemosynthesis Biology 11th year - 11th year Geology Index - Index Resources biogeographic Resources - Biology 12
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