1. Exam next Friday Proposal:
60 point 4th exam over chapters 10 (Lipids), 11 (Membranes), 13 (Bioenergetics (ATP & redox)
140 point final: ~40 points new stuff (general concepts in glycolysis, TCA, electron transport), ~100 points “comprehensive”
Review sheet (4th exam) this weekend
Review for 4th exam on Tuesday(?)
Review for final ~ couple of days next week

2. Fats/Carbohydrates/Proteins (highly reduced compounds)
Nutrients:
Fats/Carbohydrates/Proteins (highly reduced compounds)
Glycolysis, TCA/Krebs cycle
Breakdown of nutrients
Harvesting of energy as
(some) ATP, lots of reducing power (NADH)
Oxidative phosphorylation (Electron transport)
Harvesting of energy from reducing agents
Generation of (lots of) ATP
Usable (bioavailable) chemical energy:
ATP (other phosphorylated cpds), reducing agents (eg. NADH)

3. Aerobic respiration of glucose (etc)
Glycolysis:
Start with glucose (6 carbon)
Generate some ATP, some NADH, pyruvate (2 x 3 carbon)
TCA cycle
Start with pyruvate
Generate acetate
Generate CO2 and reduced NADH and FADH2
Electron transport
Start with NADH/FADH2
Generate electrochemical H+ gradient
Oxidative phosphorylation
Start with H+ gradient and O2 (and ADP + Pi)
Generate ATP and H2O

4. Glycolysis Pathway for D-glucose degradation Generation of pyruvate
Anerobic (no O2 required)
Occurs in most every living cell
Eukaryotes→ in cytosol
Pyruvate has different fates
Aerobic→CO2→ ATP
Anerobic
Fermentation to EtOH
Fermentation to lactate

5. Glycolysis 5 step preparatory phase Energy requiring 2 ATP invested
Phosphorylation
Isomerization
Cleavage

6. Why phosphorylation? Coupled transfer of phosphate to/from ATP
Intermediates “trapped” within the cell
Energy required to keep ‘naked’ glucose in the cell (vs. chemical gradient)
Phosphate groups (neg charge) easily retained
Binding energy
Enzymes take advantage of negative charge to increase affinity/specificity

7. Glycolysis 5 step payoff phase 4 ATP generated (net 2 gained)
2 NADH gained
2 pyruvate
Series of oxidation and phosphorylation steps

8. Step 1: Glucose phosphorylation by hexokinase

9. Step 2: Conversion to Fructose-6-P

10. Step 3:Phosphorylation to F-1,6-bisP
phosphofructokinase
*Committed step*
Regulatory enzyme

11. Step 4: Cleavage of F-1,6-bP
6 carbon sugar →
Two 3 carbon sugars (triose phosphates)

12. Step 5: isomerization of dihydroxyacetone
Both 3 carbon sugars are
now the same
(glyceraldehyde 3-P)

13. “Payoff phase” Step 6: oxidation (phosphorylation) of G-3-P

14. Step 7: ATP formation Steps 6 & 7 Overall: transfer of Pi from
glyceraldehyde 3-P to ATP with
1,3-BPG as an intermediate
“Substrate-level phosphorylation”

15. Step 8: Rearrangement to 2-phosphoglycerate

16. Step 9: Dehydration of 2-phosphoglycerate to PEP

17. Step 10: Phosphoryl transfer to ADP