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

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

5. Glycolysis 10-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 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?

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

7. Adenosine Tri-Phosphate

8. Nicotinamide Adenine Dinucleotide

9. Nicotinamide Adenine Dinucleotide 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)-CoA
2 Pyruvate + 2 CoA + 2 NAD+  Acetyl-CoA + 2 CO2 + 2 NADH

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

13. Kreb’s Cycle Squeezing the energy out of acetyl-CoA!!!
Roles 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
acetyl-CoA
Squeezing the energy out of acetyl-CoA!!!

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

15. FADFADH2 Flavin Adenine Dinucleotide

16. Energy Production from Krebs Cycle
Acetyl-CoA + 3 NAD+ + ADP + Pi → 3 NADH + ATP + 2 CO2 Wait we had two pyruvates to start… have to multiply above by 2!! 2 Acetyl-CoA + 6 NAD+ + 2 ADP + 2Pi → 6 NADH + 2 ATP + 4 CO2

17. Energy Production So far…
Glycolysis: 2ATP, 2 NADH
Intermediate Step: 2 NADH
Kreb’s Cycle: 2 ATP, 6 NADH, 2 FADH2
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 ATP
Intermediate step: 2 NADH= 6 ATP
Krebs: 2 ATP; 6 NADH =18 ATP; FADH2 = 4 ATP
34 ATP from ETC
2 ATP from Glycolysis
2 ATP from Kreb’s directly
Total ATP production= 38 ATP