1. Recap: structure of ATP
ribose
guanine
inorganic phosphate
deoxyribose
thymine
organic phosphate
nicotinamide
cytosine
adenine
flavine

2. Recap: where in the cell?
Glycolysis
Phosphorylation
Oxidation
Link reaction
Krebs cycle
Oxidative phosphorylation

3. Recap: glycolysis

4. Recap: link reaction

5. Recap: Krebs cycle

6. Enzymes Glycolysis: Krebs cycle: Phosphofructokinase Decarboxylases
Dehydrogenases

7. phosphofructokinase enzyme
Regulatory enzymes
glucose
↑ ATP
↑ citrate
↑ ADP
↓ ATP
↓ citrate
phosphofructokinase enzyme
pyruvate
Krebs
cycle

9. How much ATP has been produced?
Glycolysis:
Link reaction:
Krebs cycle:
Is this enough???

10. The electron transport chain

11. The electron transport chain
Hydrogen atoms released from NADH and FADH as they are oxidised
Hydrogen atoms split into protons and electrons
Electrons move along the electron transport chain, losing energy at each carrier
Energy is used to pump protons into intermembrane space forming an electrochemical gradient
Protons move down electrochemical gradient back to matrix via ATP synthase
Movement of protons drives synthesis of ATP from ADP and inorganic phosphate
Protons, electrons and oxygen combine to form water, the final electron acceptor

12. Evidence for chemiosmosis
pH of intermembrane space is lower than pH of matrix
Proton gradient exists between intermembrane space and matrix
Artificial vesicles created with proton pump proteins resulted in ↓ pH in vesicle
Proton gradient can be used to synthesise ATP
Mitochondria in pH8 solution produced no ATP
Proton gradient can be used by mitochondria to make ATP
Uncouplers destroyed proton gradient in mitochondria
Proton gradient is required by mitochondria to make ATP

13. In 1997 1 NADH → 3 ATP and 1 FADH → 2 ATP!
How much ATP?
Oxidative phosphorylation makes ATP using energy from NADH and FADH
1 NADH → 2.5 ATP
1 FADH → 1.5 ATP
More cutbacks:
In NADH → 3 ATP and 1 FADH → 2 ATP!

14. How much ATP? Stage of respiration Molecules produced
Number of ATP molecules
Glycolysis
Link reaction (x2)
Krebs cycle (x2)
Total ATP =

15. Anaerobic respiration
glucose
pyruvate
carbon dioxide + ethanal
lactic acid
ethanol

16. Aerobic and anaerobic respiration
Where?
Is oxidation complete?
What are the waste products?
How much energy?
Where?
Is oxidation complete?
What are the waste products?
How much energy?