1. Lecture 5 Outline (Ch. 9) Respiration Overview Redox Reactions
NAD+/NADH
Glycolysis
Pyruvate Oxidation
VI. Summary

2. Cellular Respiration Overall purpose: • convert food to energy
• animals AND plants
• complementary to photosynthesis

3. Cellular Respiration Cellular Respiration: (Exergonic)
• catabolizes sugars to CO2
• requires O2
• at mitochondrion

4. Redox Reactions • as part of chemical reaction, e- are transferred
• e- transfer = basis of REDOX reactions
(reduction) (oxidation)

5. ZH2 + O2 yields ZO + H2O • follow the H, e- move with them
Redox Reactions
Use “H rule” for reactions in this class
Reactant with more H’s = e donor, will be oxidized
Reactant with more O’s = e acceptor, will be reduced
ZH2 + O2 yields ZO + H2O
• follow the H, e- move with them

6. Self-Check Reaction Molecule Reduced Molecule Oxidized
ZH2 + O2 yields ZO + H2O
CH4 + 2O2 yields CO2 + 2H2O
C6H12O6 + O2 yields CO2 + H2O
C8H18 + O2 yields CO2 + H2O
Oxygen
ZH2

7. Redox Reactions
• transfer of e- to oxygen is stepwise

8. Redox Reactions • e- moved by NAD/H (from niacin/vit B3)
• NADH  carry e- (reduced!)
• NAD+  not carrying e- (oxidized!)
Where do e- come from?
Where do e- go?
• glucose NADH ETC O2 (makes H2O)

9. In this equation NAD+ is converted to NADH.
NAD+ + H+ + 2e-  NADH
a. Which is the organic compound reactant?
b. Did this reactant gain or lose electrons to become the product?
c. Is this reactant oxidized or reduced to make the product?

10. • Steps of respiration:
1. glycolysis
2 CO2
2. Pyruvate oxidation
3. Citric acid cycle
4 CO2
4. ETC & oxidative phosphorylation

11. Cellular Respiration 1. Glycolysis • 1 glucose (6C) 2 pyruvate (3C)
• Keep track of:
- inputs/outputs
plus:
ATP/ADP
- Electron carriers
CO2 O2
• eukaryotes AND prokaryotes

12. Glycolysis Glucose-6-phosphate 2 Fructose-6-phosphate Glucose ATP 1
ADP 1
Glucose
Glucose-6-phosphate 2
Glucose-6-phosphate
Fructose-6-phosphate

13. Glycolysis ATP ADP Fructose- 1, 6-bisphosphate 4 5 Dihydroxyacetone
Glyceraldehyde-
3-phosphate 4 5

14. Glycolysis 2 ADP 3 steps not shown 2 ATP 2 NAD+ 2 NADH 2
Phosphoenolpyruvate
Pyruvate 10
2 NADH
2 NAD+

15. In glycolysis….. a. Is any O2 or CO2 used or produced?
b. How many ATP are used? How many are produced? What is the NET ATP production?
c. Where do the phosphates come from to make ATP?
d. What are the outputs of glycolysis and where do these molecules go?

16. Energy production
Mitochondria
• energy from nutrients  ATP

17. Where do the outputs go? Cellular Respiration
2. Pyruvate Oxidation (coenzyme junction)
• 2 pyruvate (3C) Acetyl CoA (2C)
• pyruvate joins coenzyme A (from vitamin B5)
• 2 carbons lost (as CO2)
Where do the outputs go?
• 2 NAD+  2 NADH

18. At home Match each Step Name with Energy Balance and Basic Reaction