Energy Generation in Respiration: ATP Production and Cell Function

1. Respiration BIO 1113/1114 Oklahoma City Community College Dennis Anderson

2. All Life Needs Energy • Energy is needed to negate the effects of the Second Law of Theremodynamics • Energy must be in the form of ATP

3. Energy Structure of ATP Adenine Phosphates Ribose

4. Energy

5. Respiration • The process of generating ATP • Three phases • Glycolysis • Kreb’s Cycle • Electron Transport System (ETS)

6. OH OH OH H OH H H C C C C C C O H H H OH H Energy stored in covalent bonds Glucose

7. Glucose NADH ATP NADH ATP Pyruvic Acid Pyruvic Acid Alcohol Alcohol Glycolysis

8. Essay Box ArtYeast Inside, Performing Fermentation

9. Glucose NADH ATP NADH ATP Pyruvic Acid Pyruvic Acid Lactic Acid Lactic Acid Glycolysis

10. Figure 7.6Energy Transfer in the Mitochondria cell outer membrane inner membrane mitochondrion glycolysis outer membrane Krebs cycle outer compartment electron transport chain e– O2 H+ inner membrane H2O inner compartment

11. Pyruvic Acid Acetyl Carbon Dioxide

12. Acetyl Kreb’s Cycle NADH ATP Carbon Dioxide

13. Figure 7.3 The Electron Carrier NAD+ Step 1 empty 1. NAD+ within a cell, along with two hydrogen atoms that are part of the food that is supplying energy for the body.

14. Figure 7.3 The Electron Carrier NAD+ Step 2 empty loaded proton (oxidized) (reduced) 1. NAD+ within a cell, along with two hydrogen atoms that are part of the food that is supplying energy for the body. 2. NAD+ is reduced to NAD by accepting an electron from a hydrogen atom. It also picks up another hydrogen atom to become NADH.

15. Figure 7.3 The Electron Carrier NAD+ Step 3 empty loaded empty goes to pick up more electrons proton (oxidized) used in later stage of respiration (reduced) used in later stage of respiration 1. NAD+ within a cell, along with two hydrogen atoms that are part of the food that is supplying energy for the body. 2. NAD+ is reduced to NAD by accepting an electron from a hydrogen atom. It also picks up another hydrogen atom to become NADH. 3. NADH carries the electrons to a later stage of respiration then drops them off, becoming oxidized to its original form, NAD+.

16. Electron Transport System Oxygen ATP H+ NADH Water e-

17. Figure 7.4aOverview of Energy Harvesting (a) In metaphorical terms insert 1 glucose 2 energy tokens glycolysis 2 energy tokens Krebs cycle 32 energy tokens electron transport chain Just as the video games in some arcades can use only tokens (rather than money) to make them function, so our bodies can use only ATP (rather than food) as a direct source of energy. The energy contained in food—glucose in the example—is transferred to ATP in three major steps: glycolysis, the Krebs cycle, and the electron transport chain. Though glycolysis and the Krebs cycle contribute only small amounts of ATP directly, they also contribute electrons (on the left of the token machine) that help bring about the large yield of ATP in the electron transport chain. Our energy-transfer mechanisms are not quite as efficient as the arcade machine makes them appear. At each stage of the conversion process, some of the original energy contained in the glucose is lost to heat.

18. Kreb’s Cycle & ETS Glycolysis

19. Mitochondria • Similar to prokaryotic cells • Size • Own DNA • Make their own proteins • Reproduce

21. Summary • Glycolysis produces ATP without oxygen • Anaerobic • Glycolysis only makes 2 ATP molecules • Pyruvic Acid • Enters Kreb’s Cycle if oxygen is present • Ferments with no oxygen • ETS produces the most ATP molecules • Aerobic

22. The End