Explain in brief full mechanism of photosynthesis.(200-300 words)
Photosynthesisis a process used by plants and other organisms to convert light energy into chemical energy that can be laterused as afuel of the organisms' activities.Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll pigments. Proceeding these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. Furthermore, two further compounds are generated: reducednicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), the "energy currency" of cells. The second part of photosynthesis is light-independent whereas sugars are produced. It goes by a subsequent sequence of reactions called the Calvin cycle. During this cycle atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate. Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reduced and removed to form further carbohydrates, such as glucose. The overall equation for the light-dependent reactions could be for green plants the following: 2 H2O + 2 NADP++ 3 ADP + 3 Pi+ light → 2 NADPH + 2 H++ 3 ATP + O2 The overall equation for the light-independent reactions in green plants is: 3 CO2+ 9 ATP + 6 NADPH + 6 H+→ C3H6O3-phosphate + 9 ADP + 8 Pi+ 6 NADP++ 3 H2O.
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