1. Glycolysis, Krebs Cycle, and Electron Transport System A review for the confused (like me!) Regina Lamendella AP Biology December 16, 2008

2. What is happening while you ingest donuts??

3. Doughnut = glucose = electrons = Electrons What is the purpose of glycolysis and cellular respiration?

4. Overview Video Write down the major “take home messages” from the video

5. Glycolysis 10-STEP reaction10-STEP reaction (Rxns 1-5) Glucose is phosphorylated and cleaved to yield 2 molecules of triose glyceraldehyde-3-phosphate. This process uses two ATPs.(Rxns 1-5) Glucose is phosphorylated and cleaved to yield 2 molecules of triose glyceraldehyde-3-phosphate. This process uses two ATPs. (Rxns 6-10): The molecules of glyceraldehyde- 3-phosphate are converted to pyruvate, with concomitant generation of four ATPs and two NADH per glucose.(Rxns 6-10): The molecules of glyceraldehyde- 3-phosphate are converted to pyruvate, with concomitant generation of four ATPs and two NADH per glucose. How many net ATPs?How many net ATPs?

6. Glycolysis Where are we within the cell?Where are we within the cell? What does ATP stand for?What does ATP stand for? What does NAD stand for?What does NAD stand for? How many carbons does pyruvate have?How many carbons does pyruvate have? 2 NAD+ 1 ATP

7. Adenosine Tri-Phosphate

8. Nicotinamide Adenine Dinucleotide

9. Nicotinamide Adenine Dinucleotide H H

10. Overall reaction for glycolysis Glucose + 2 NAD+ + 2 ADP + 2 Pi  2 NADH + 2 pyruvate + 2 ATP Where do the pyruvate go next?

11. Intermediary Reaction Pyruvate (3-Carbon)  Acetyl (2-Carbon)-CoAPyruvate (3-Carbon)  Acetyl (2-Carbon)-CoA 2 Pyruvate + 2 CoA + 2 NAD +  2 Acetyl-CoA + 2 CO 2 + 2 NADH2 Pyruvate + 2 CoA + 2 NAD +  2 Acetyl-CoA + 2 CO 2 + 2 NADH

12. Overall energy production so far… Glycolysis: 2 ATP, 2 NADHGlycolysis: 2 ATP, 2 NADH Intermediate reaction: 2 NADHIntermediate reaction: 2 NADH

13. Kreb’s Cycle Roles of the Krebs cycleRoles of the Krebs cycle –Generate energy by oxidizing acetyl-CoA to carbon dioxide and water –Supply biochemical intermediates for other pathways –Entry point of various degradative pathways for energy generation Squeezing the energy out of acetyl-CoA!!! acetyl-CoA

14. Krebs Cycle Where are we?Where are we? What is ATP?What is ATP? What is NAD?What is NAD? What is FAD?What is FAD? How much energy is produced?How much energy is produced?

15. FAD  FADH2 Flavin Adenine Dinucleotide H H 

16. Energy Production from Krebs Cycle Acetyl-CoA + 3 NAD + + ADP + P i → 3 NADH + ATP + 2 CO 2 3 NADH + ATP + 2 CO 2 Wait we had two pyruvates to start… have to multiply above by 2!! 2 Acetyl-CoA + 6 NAD + + 2 ADP + 2P i → 6 NADH + 2 ATP + 4 CO 2 6 NADH + 2 ATP + 4 CO 2

17. Energy Production So far… Glycolysis: 2ATP, 2 NADHGlycolysis: 2ATP, 2 NADH Intermediate Step: 2 NADHIntermediate Step: 2 NADH Kreb’s Cycle: 2 ATP, 6 NADH, 2 FADH 2Kreb’s Cycle: 2 ATP, 6 NADH, 2 FADH 2 Where to next?Where to next?

18. Electron Transport System Video Take notes and write down main points.

19. Electron Transport System Electron transport chains are redox reactions that transfer electrons from an electron donor to an electron acceptor. The transfer of electrons is coupled to the translocation of protons across a membrane, producing a proton gradient. The proton gradient is used to produce useful work. NADH= 3 ATP FADH2= 2 ATP

20. Total energy production after ETC Glycolysis: 2ATP; 2 NADH= 6 ATPGlycolysis: 2ATP; 2 NADH= 6 ATP Intermediate step: 2 NADH= 6 ATPIntermediate step: 2 NADH= 6 ATP Krebs: 2 ATP; 6 NADH =18 ATP; 2 FADH 2 = 4 ATPKrebs: 2 ATP; 6 NADH =18 ATP; 2 FADH 2 = 4 ATP 34 ATP from ETC34 ATP from ETC 2 ATP from Glycolysis2 ATP from Glycolysis 2 ATP from Kreb’s directly2 ATP from Kreb’s directly Total ATP production= 38 ATPTotal ATP production= 38 ATP