Cellular Respiration Essay

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Cellular respiration is the chemical process that generates energy by breaking down food molecules when oxygen is present (Prentice Hall). The chemical equation of cellular respiration is 6O2 + C6H12O6 6CO2 + 6H2O + Energy, meaning the reactants of cellular respiration are oxygen and glucose while the products are carbon dioxide, water, and energy (Gregory). Cellular respiration is crucial to life because it provides all cellular processes with the energy needed in order to function. This process involves glycolysis, the Krebs Cycle, and the electron transport chain (Dr. Fankhauser). Glycolysis, which occurs in the cytosol of the cell, is the anaerobic catabolism of glucose that leads to the release of energy and the production of two molecules of pyruvic acid (Gregory). In this stage of cellular respiration, the cell will contribute two adenosine triphosphate (ATP) molecules as activation energy, but finish with four ATP molecules after glycolysis has taken place (Dr. Fankhauser). A reaction of glycolysis extracts four high-energy electrons and transfers them to nicotinamide adenine dinucleotide (NAD+, an electron acceptor). After accepting a pair of high-energy electrons, NAD+ becomes NADH, an electron carrier, and keeps the electrons till they are able to be transfer to different molecules. NAD+ can transfer energy from glucose to different places in the cell by doing so (Prentice Hall). The Krebs Cycle, which occurs in the mitochondrial matrix of the cell, is the aerobic process in which the pyruvic acid that comes from glycolysis is used to produce carbon dioxide (CO2), NADH, ATP, and flavine adenine dinucleotide (FADH2) (Gregory). In this cycle, pyruvic acid is broken down into CO2 in an array of energy-withdrawing re... ... middle of paper ... ...y both plants and animals, however, photosynthesis is performed only by plants. This is because animals are unable to produce their own food and must ingest it. The two processes take place in different parts of the cell; photosynthesis takes place in chloroplasts while cellular respiration occurs in the mitochondria (Prentice Hall). Cellular respiration allows organisms to convert food into usable energy through glycolysis, the Krebs Cycle, and the electron transport chain. The net ATP production from a single glucose molecule through cellular respiration is 36 ATP molecules, with two ATP molecules from glycolysis, two ATP molecules from the Krebs Cycle, and 32 ATP molecules from the electron transport chain. Because cellular respiration plays an important role in helping an organism function properly, an organism would die without this process (Dr. Fankhauser).
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