Cell Energy Week 3

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Associate Program Material Cell Energy Worksheet Answer the following questions: Cellular respiration: • What is cellular respiration and what are its three stages? Cellular respiration requires two cells to exchange two gases with its surroundings. The three stages of cellular respiration are Glycolysis, Citric Acid Cycle, and Electron Transport. • What is the role of glycolysis? Include the reactants and the products. Where does it occur? During glycolysis, a six carbon glucose molecule is broken in half, forming two three carbon molecules. The three carbon molecules then donate high energy electrons to NAD, the electron carrier, forming NADH. This process occurs in the cytosol of a cell. • What is the role of the citric acid cycle? Include the reactants and the products. Where does it occur? The citric acid cycle takes certain compounds that donate protons and electrons to the electron transport chain. The electron transport chain then generates ATP through the process of oxidative phosphorylation. Krebs cycle also produces two ATP through the process of substrate phosphorylation. This process occurs in the mitochondria. • What is the role of the electron transport system? Include the reactants and the products. Where does it occur? An electron transport chain functions as a chemical machine that uses the energy released by the “fall” of electrons to pump hydrogen ions across the inner mitochondrial membrane. The energy stored by electron transport behaves something like the elevated reservoir of water behind a dam. There is a tendency for hydrogen ions to gush back to where they are less concentrated, just as there is a tendency for water to flow down a hill. The inner membrane, analogous to the dam, temporarily restrains hydrogen ions. The energy of dammed water can be
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