4.4 Overview of Cellular Respiration KEY CONCEPT The overall process of cellular respiration converts sugar into ATP using oxygen. Cellular respiration is an aerobic process with two main stages.

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 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 Glycolysis happens before respiration. –anaerobic process (does not require oxygen) –takes place in cytoplasm –splits glucose into two three-carbon molecules –produces two ATP molecules –The products of glycolysis enter cellular respiration when oxygen is available.

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 The Krebs cycle is the first main part of cellular respiration. 1.Pyruvate is broken down, CO 2 is released and NADH is produced 2.Coenzyme A (CoA) bonds to 2-C molecule

4.4 Overview of Cellular Respiration 3. Citric acid (6-C chain) is formed. 4. Citric acid is broken down, CO 2 is released, and NADH is made C chain is broken down, CO 2 is released, and NADH & ATP is made C chain is rearranged and NADH and FADH 2 is made. 7. Krebs cycle The Krebs cycle produces energy-carrying molecules.

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 Step 2: 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 electron transport chain is the second main part of cellular respiration. The electron transport chain uses NADH and FADH 2 to make ATP. 1.high-energy electrons removed from NADH and FADH2 2.H + ions move across the membrane. 3.ADP turns into ATP by use of the ATP Synthase. 4.Water is made from O, 2H + & 2e -.

4.4 Overview of Cellular Respiration The breakdown of one glucose molecule produces up to 38 molecules of ATP. The electron transport chain is the second main part of cellular respiration. The electron transport chain uses NADH and FADH 2 to make ATP.