Chapter 8 Cellular Respiration

Study Guide—Exam 3 covers Ch. 7, 8, 9, and 10 Chapter 8: Cellular Respiration Make sure to define BOLDED terms. Complete this study guide as you learn the chapter, then use it to help you complete your assignment and/or study for the quiz and/or exam. 8.1 Cellular Respiration 1. Explain the role of cellular respiration in a cell (including ATP). a. Break down glucose to create ATP 2. Describe the structure and function of a mitochondrion, including intermembrane space, cristae, matrix, inner membrane, outer membrane. a. Intermembrane space i. Where the H+ concentration gradient is established b. Cristae i. Folds of the inner membrane c. Matrix i. “cytoplasm” of the mitochondria 3. State and interpret the overall reaction for cellular respiration (glucose breakdown). a. Glucose + O2 CO2 + H2O + ATP 4. Identify the coenzymes used in cellular respiration (NAD+, FAD). a. NAD+ i. Both oxidized and reduced ii. Accepts electrons and one H+ to become NADH b. FAD i. Both oxidized and reduced ii. Accepts electrons and two H+ to become FADH2 5. List and summarize the four stages/phases of cellular respiration (glycolysis, preparatory reaction, citric acid cycle, electron transport chain) and identify the location of each within the cell. a. Glycolysis i. Breakdown glucose into pyruvate ii. Occurs in the cytoplasm iii. Reactant: glucose; product: pyruvate iv. Energy investment 1. Two ATP molecules are broken down to “activate” glucose a. They give phosphates to the glucose, allowing it to split into two G3P molecules v. Energy harvesting 1. G3P molecules are oxidized ultimately into pyruvate 2. As G3P is oxidized, you gain a total of 4 ATP molecules (net gain of 2) b. Prep reaction i. Pyruvate is prepped (it is oxidized into acetyl CoA) ii. Occurs in the matrix iii. Pyruvate is oxidized into an acetyl group which binds to Coenzyme A creating acetyl CoA iv. Reactant: pyruvate; product: acetyl CoA c. Citric acid cycle i. Oxidizing citric acid to create multiple NADH and FADH2 ii. Occurs in the matrix iii. Acetyl group is bound to a 4-carbon molecule creating citric acid 1. The citric acid is then oxidized to create many NADHs and FADH2s iv. Reactant: citric acid; product: NADHs and FADH2s d. ETC i. ii. iii. iv. Create ATP and H2O Occurs in the cristae Reactants: NADH, FADH2; Products: ATP and H2O NADH and FADH2 donate their electrons and H+ to the ETC 1. Those electrons travel down the ETC and release energy, allowing H+ to be carried into the intermembrane space, creating a concentration gradient 2. Those H+ then flow down the concentration gradient back into the matrix via the ATP synthase complex 3. When they flow through the ATP synthase complex, This allows for ATP to be created from ADP and P 8.2 Outside the Mitochondria: Glycolysis 6. Explain the role of glycolysis in a cell. a. See question 5 7. Define the energy-investment and energy-harvesting steps of glycolysis and summarize the use, production, and net gain of ATP. a. See question 5 8. Describe the overall glycolysis reaction, including beginning reactants (inputs), and final products (outputs). a. See question 5 8.3 Outside the Mitochondria: Fermentation 9. Explain the role of the fermentation pathway in biological organisms. a. Occurs when O2 is not present b. Occurring in the cytoplasm c. Pyruvate is reduced into either lactate or ethyl alcohol d. Alcohol fermentation i. Yeasts ii. Producing alcohol and bread e. Lactic acid fermentation i. Animals ii. Produces cheese, yogurt, sauerkraut 10. Compare lactic acid fermentation (animals, some bacteria) and alcohol fermentation (some bacteria, fungi), including cell location, beginning reactants (inputs), final products (outputs). See question 9 11. Give examples of products that are produced by fermentation. a. See question 9 8.4 Inside the Mitochondria 12. Identify the purpose of the preparatory reaction in cellular respiration. a. Convert pyruvate into acetyl CoA i. Pyruvate is oxidized into an acetyl group which binds to coenzyme A creating acetyl CoA b. See question 5 13. Describe the overall preparatory reaction, including beginning reactants (inputs), and final products (outputs). See question 5 14. Describe the overall citric acid cycle reactions, including beginning reactants (inputs), and final products (outputs). a. Acetyl group binds to a 4-C molecule to create citric acid b. Citric acid is oxidized twice by NAD+, giving off 2 CO2 c. ATP is produced d. The remaining 4-C molecule is oxidized twice more to return it to the original 4-C molecule that binds to the acetyl group e. Products: ATP, NADH, FADH2 15. Describe the overall electron transport chain reactions, including beginning reactants (inputs), and final products (outputs), roles of NADH and FADH2, final electron acceptor, ATP synthase. 8.5 Metabolism 16. Identify the three types of biomolecules that can be used as an energy source for cellular respiration.