1. Bio 178 Lecture 16 Cellular Respiration http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookGlyc.html

2. Reading Chapter 9 Quiz Material Questions on P 184 Chapter 9 Quiz on Text Website (www.mhhe.com/raven7)

3. Outline Cellular Respiration  Glucose catabolism (cntd.)

4. Acetyl-CoA Production Function Oxidation of pyruvate to produce NADH Overall Reaction Pyruvate (3C) + CoA + NAD +  Acetyl-CoA (2C) + CO 2 + NADH Catalyzed by pyruvate dehydrogenase Coenzyme A is a cofactor Location Pyruvate is shuffled into the mitochondrion. Acetyl co-A is made in the mitochondrial matrix.

5. Pyruvate Oxidation

6. Krebs Cycle Acetyl-CoA (2C)  2CO 2 + 3NADH + FADH 2 + ATP Location Mitochondrial matrix Description 9 enzyme controlled reactions that can be divided into 2 major stages: 1. Priming Preparation for energy extraction. 2. Energy Harvesting

7. Krebs Cycle

9. Bookkeeping - Glycolysis, Acetyl-CoA & Krebs Cycle (Net Products/Glucose) ProcessATPNADHFADH 2 Glycolysis 220 Acetyl-CoA Production 020 Krebs Cycle 262 Total 4102

10. Electron Transfers and Energy Why is Glucose an Energy Rich Food? C-H bonds are shared equally between the atoms  the electrons are far away from the atoms. Electronegative atoms pull electrons close to their atoms  lower potential energy. Electrons transferred from glucose to oxygen release energy, which is used to make ATP.

11. Electron Transfers and Energy Energy is Harvested in small Steps Less energy is lost as heat if it is transferred in incremental steps.  Electrons are stripped off glucose in glycolysis and Krebs cycle in stages. These electrons and a hydrogen are transferred to NAD +. NADH transfers its electrons to O 2 in small steps via the electron transport chain so that the cell can harvest a lot of energy. Each step in the chain involves moving the electrons to a slightly more electronegative carrier  they move down an energy gradient.

12. Oxidation and Reduction of Nicotinamide

13. The Electron Transport Chain

14. Location Across the inner mitochondrial membrane. Product ATP Pathway of Electron Transfers NADH and FADH 2 each transfer 2 electrons to the chain. The energy lost by each electron as it moves through the chain is used to drive a proton pump. NADH activates 3 pumps & FADH 2 activates 2. The final protein in the chain uses the electrons to reduce oxygen to form water.

15. The Electron Transport Chain (Cntd.) Electrochemical Gradient Pumping protons across the membrane produces both a chemical gradient and an electrical gradient (intermembrane space more positive). Chemiosmosis is used to Produce ATP Protons diffuse back into the matrix through ATP synthase, which uses the energy of the gradient to synthsize ATP.

16. Chemiosmosis

17. Aerobic Respiration and the Electron Transport Chain McGraw-Hill Video

18. How Many ATP are made by Electron Transport? How Many Proton pumps? 10 NADH & 2 FADH 2 are used in electron transport: 1 NADH activates 3 proton pumps  30 proton pumps. 1 FADH 2 activates 2 proton pumps  4 proton pumps. How Many ATP? 1 ATP made per proton pump. 2 NADH made by glycolysis in cytoplasm. Takes 1 ATP to pump 1 NADH into mitochondrion. 34 ATP - 2 ATP = 32 ATP net

19. Theoretical ATP Yield by Aerobic Respiration Per glucose molecule: Process# ATP Glycolysis2 Krebs Cycle2 Electron Transport32 Net36 Actual Yield 30 molecules ATP