1. What you should know from today’s lecture • The importance of glycolysis, fermentation, and respiration (Krebs cycle) in biology • The site of glycolysis, fermentation, and respiration in prokaryotes and eukaryotes • Overall chemical reactions of glycolysis, fermentation, and respiration • Mitochondrion structure • Poisons affecting respiration

2. The importance of glucose metabolism • The most primitive and universal method for capturing and converting chemical energy • Performed by all organisms, auto- and heterotrophs • Fermentation pathways are ancient but inefficient • Aerobic respiration is efficient but requires oxygen (from photosynthesis)

3. Energy release from glucose Glucose (6 C) Glycolysis 2 ATP Lactate fermentation Alcoholic fermentation 2 Pyruvate (3 C) Lactate (3 C) Ethanol (2 C) + CO2 6O2 Aerobic respiration 34-36 ATP 6 CO2 + 6 H2O

4. Glycolysis: overview • All cells can perform glycolysis -- universal source of energy (ATP) and carbon skeleton • Glycolysis takes place in the cytoplasm What is NAD+?

5. Glycolysis I Fig. 8.4b, p. 135

6. Glycolysis II Fig. 8.4c, p. 135

7. Aerobic respiration: overview • Aerobic respiration takes place in the cytoplasm and membrane of prokaryotes, and in the mitochondria of eukaryotes

8. Aerobic respiration Fig. 8.6, p. 137

9. Mitochondrion (see next slide) Fig. 8.5a, p. 136

10. Chemiosmotic ATP formation Fig. 8.5b, p. 136

11. ATP yield from aerobic respiration

12. Fermentation Lactate fermentation Lactate dehydrogenase (LDH) Site of lactate fermentation: Examples of lactate fermentation: Alcoholic fermentation Site of alcoholic fermentation: Examples of alcoholic fermentation:

13. Metabolic poisons

14. Metabolism Fig. 8.12, p. 143