Biology

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There are many differences between photosynthesis and cellular respiration. Photosynthesis requires energy as photons. Cellular respiration supplies energy in the form of ATP. In photosynthesis, electron transport occurs in the membranes of chloroplasts or thylakoid discs. Cellular respiration takes place in the membranes of mitochondria. In photosynthesis, water breaks down to supply 2 electrons and 2 Hydrogen ions and release ½ O at the beginning of the chain. In cellular respiration, 2 electrons at the end of the chain combine with 2 Hydrogen ions and ½ O to produce water. This is the complete opposite. NADPH + H is produced at the end of the chain in photosynthesis. In respiration, it is fed into the beginning of the chain and in the last step of photosynthesis. In respiration, the first step the breakdown of pryuvic acid. The Calvin cycle requires NADPH plus a Hydrogen ion and takes place in the stroma. The Krebs' cycle produces NADH plus a Hydrogen ion and takes place in the matrix. Photosynthesis takes in carbon dioxide and water and produces glucose. Cellular respiration is the counterpart. It takes in glucose and produces carbon dioxide and water. Photosynthesis is the storage of energy in carbon compounds. In photosynthesis, the sun's energy is converted to chemical energy and stored in glucose molecules. In photosynthesis, we see energy associated with electrons or being released from association of electrons. There are two pathways associated with photosynthesis: light and dark reactions. I will concentrate on the non-cyclic light reactions of photosynthesis. Light reactions are driven by light energy. This pathway produces ATP and a reduced electron carrier (NADPH + H ). The overall reaction is solar energy + 6CO + 6H O -> C H O + 6O + heat. Where photosynthesis takes place in specific groups of organisms, cellular respiration is done by all cells. In respiration, the energy stored in organic compounds may have been produced by the cell itself or...
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