4.4 Overview of Cellular Respiration KEY CONCEPT The overall process of cellular respiration converts sugar into ATP using oxygen.

4.4 Overview of Cellular Respiration Objectives Describe the process of cellular respiration. Compare cellular respiration to photosynthesis.

4.4 Overview of Cellular Respiration Vocabulary Cellular Respiration –Process of producing ATP by breaking down carbon-based molecules when oxygen is present. Aerobic –Process that requires oxygen to occur. Glycolysis –Anaerobic process in which glucose is broken down into two molecules of pyruvate and two net ATP are produced. Anaerobic –Process that does not require oxygen to occur. Krebs Cycle –Process during cellular respiration that breaks down a carbon molecule to produce molecules that are used in the electron transport chain.

4.4 Overview of Cellular Respiration Cellular respiration makes ATP by breaking down sugars. Cellular respiration is aerobic, or requires oxygen. Aerobic stages take place in mitochondria. mitochondrion animal cell

4.4 Overview of Cellular Respiration Glycolysis must take place first. –anaerobic process (does not require oxygen) –takes place in cytoplasm –splits glucose into two three-carbon molecules –produces two ATP molecules

4.4 Overview of Cellular Respiration Cellular respiration is like a mirror image of photosynthesis. The Krebs cycle transfers energy to an electron transport chain. –takes place in mitochondrial matrix –breaks down three-carbon molecules from glycolysis –makes a small amount of ATP –releases carbon dioxide –transfers energy-carrying molecules 6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and Krebs Cycle

4.4 Overview of Cellular Respiration 6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and The electron transport chain produces a large amount of ATP. –takes place in inner membrane –energy transferred to electron transport chain –oxygen enters process –ATP produced –water released as a waste product Electron Transport

4.4 Overview of Cellular Respiration The equation for the overall process is: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O The reactants in photosynthesis are the same as the products of cellular respiration.

4.4 Overview of Cellular Respiration Question/Answer What is the function of cellular respiration? –Cellular respiration breaks down sugars to produce ATP for cell activities. What process leads to cellular respiration, and where does it take place? –Glycolysis, which occurs in the cytoplasm Does glucose actually react with oxygen during cellular respiration? Explain. –No, glucose is split by glycolysis prior to the aerobic parts of cellular respiration, when oxygen enters the process. Where does cellular respiration occur? –Mitochondria What are the reactants and products of cellular respiration? –The reactants are three-carbon molecules and oxygen. The products are water and carbon dioxide.