Lesson 5.4 - Citric Acid Cycle PDF

Lesson 5.4 Cellular Respiration – Citric Acid Cycle 1 Do now: (you have 3 minutes) How do we find out the NET gain of ATP of glycolysis? What are the products of glycolysis? ET...

Lesson 5.4 Cellular Respiration – Citric Acid Cycle 1 Do now: (you have 3 minutes) How do we find out the NET gain of ATP of glycolysis? What are the products of glycolysis? ET C Citric Acid 2 Cycle  2 Pyruvic Acid Citric Acid Cycle Oxygen is required In the presence of oxygen, pyruvic acid produced in glycolysis passes to mitochondrial matrix for Citric Acid Cycle (Krebs cycle). Key event: Pyruvic acid is broken down into CO2 in a series of energy-releasing reactions. Pyruvic Acid Oxidation (changes in PA before Krebs cycle begins) One carbon molecule is removed from pyruvic acid forming acetate CO2 is released NAD+ reduces to NADH. Pyruvic Acid Oxidation Coenzyme – An organic molecule (non-protein) that is required for the proper functioning of an enzyme. Coenzyme A joins the acetate, forming acetyl-CoA. Citric Acid Cycle Key steps: 1. Acetyl Co-A enters citric acid cycle by combining with a 4C compound (OAA) 2. The reaction forms 1st stable product i.e. Citric acid 3. Citric acid is broken down into a 5- carbon compound, then into a 4- carbon compound. 4. OAA is regenerated  Citric Acid Cycle Products/energy released during Krebs cycle per Pyruvate: Two more molecules of CO2 are released Electrons join NAD+ and FAD, 3NADH and 1 FADH2 are formed One molecule of ATP is generated Citric Acid Cycle-What I need to know… The citric acid cycle + Pyruvate Oxidation breaks down 1 pyruvate molecule into 3 CO2 molecules. The energy tally from 1 molecule of pyruvic acid is 4 NADH, 1 FADH2, 1 ATP In the presence of oxygen, those high-energy electrons can be used to generate huge amounts of ATP in the electron transport chain (ETC).  Review Questions 1. What is the net gain of ATP from 1 glucose in the citric acid cycle? 2. Where does the citric acid cycle take place in the cell? 3. What is another name for the citric acid cycle? 4. What is the gain of NADH per glucose through citric acid cycle? 5. What is the gain of ATP per glucose through citric acid cycle? 6. What is the gain of FADH2 per pyruvic acid in the citric acid cycle? 7. What is the starting molecule for the citric acid cycle? 8. How much CO2 is produced per pyruvic acid through citric acid cycle? 9. What are the products released per glucose in the through Krebs cycle? 10. What are the products of Pyruvate oxidation, per glucose? 1. 2 ATP per glucose 2. In the mitochondrial matrix 3. The Krebs Cycle 4. 10 NADH per glucose (2 NADH in glycolysis; 2 in Pyruvate oxidation; 6 NADH in the citric acid cycle) 5. 4 ATP per glucose (2 ATP in glycolysis; 2 ATP in the citric acid cycle) 6. 1 FADH2 per pyruvic acid (2 FADH2 per glucose) 7. Acetyl Co-A (2 molecules per glucose) 8. 3 CO2 per pyruvic acid (6 per glucose) 9. 6 CO2, 10 NADH, 2 FADH2, 4 ATP 10. 2Acetyl Co-A, 2NADH, 2CO2  Glycolysis Citric Acid Cycle Electron Transport Chain Location Cytoplasm Mitochondrial Matrix Aerobic or Anaerobic Aerobic Anaerobic Starting C-based Glucose 2 Pyruvate (6 Carbons) molecule 2 Pyruvate 6 CO2 Ending C-based (3 Carbons each) molecule ATP Produced NET gain 2 ATP 2 ATP Electron Carriers 2 NADH 8 NADH Produced 2 FADH2 Other molecules produced