1. Cellular Respiration Chapter 9

2. Food = source of energy A Calorie – is the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius. Cells don’t “burn” glucose or other foods. Instead, they gradually release the energy. The Calorie used on food labels is a kilocalorie, or 1000 calories

3. Feel the Burn Do you like to run, bike, or swim? These all are good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose, a six-carbon sugar. 1.How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? 2.What do you think is happening in your cells to cause the changes in how you feel? 3.Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer.

4. Cellular Respiration The process that releases energy by breaking down glucose & other food molecules in the presence of oxygen. 6O2 + C 6 H 12 O 6 → 6CO 2 + 6H 2 O + Energy oxygen + glucose → carbon dioxide + water + energy

5. Aerobic Respiration

6. 3 Stages make up Cellular Respiration Gycolysis Kreb Cycle Electron Transport

7. Glucose Glycolysis Krebs cycle Electron transport Fermentation (without oxygen) Alcohol or lactic acid Chemical Pathways Section 9-1

8. Glucose Glycolysis Cytoplasm Pyruvic acid Electrons carried in NADH Krebs Cycle Electrons carried in NADH and FADH 2 Electron Transport Chain Mitochondrion Figure 9–2 Cellular Respiration: An Overview Mitochondrion Section 9-1

9. 3 Stages make up Cellular Respiration Glycolysis – process in which 1 molecule of glucose is broken in half, producing 2 molecules of pyruvic acid & gains 2 ATP molecules.  O 2 present - it is followed by the Kreb Cycle & the electron transport chain.  O 2 not present (anaerobic) - it is followed by fermentation.  Fermentation – releases energy in food & converts NADH back into NAD+ keeping the supply of ATP constant.

10. Glucose To the electron transport chain Figure 9-3 Glycolysis Section 9-1 2 Pyruvic acid

11. Glycolysis

12. Fermentation Alcoholic fermentation – yeasts & a few other microorganisms; causes bread dough to rise. Lactic Acid fermentation – in muscles during rapid exercise when the body can’t supply enough O 2 to the tissues; without oxygen, the body isn’t able to produce the ATP required. Buildup causes pain & soreness.

13. Glucose Pyruvic acid Lactic acid Figure 9–4 Lactic Acid Fermentation

14. Rolling and Folding Some of the steps in cellular respiration take place in the membrane inside the cell structure called the mitochondrion, which has a folded inner membrane. What purpose do these folds serve? Section 9-2

15. Flowchart Section 9-2 Glucose (C 6 H 12 0 6 ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) Cellular Respiration

16. 3 Stages make up Cellular Respiration Kreb Cycle – requires O 2 (aerobic)  In eukaryotes.  Takes place in the mitochondria.  Aka. Citric acid cycle b/c it’s one of the first products.  Pyruvic acid is broken down into CO 2 which is released into the air.  NAD+ is changed to NADH & FAD is changed to FADH 2 which carry high-energy electrons to the electron transport chain.

17. The Krebs Cycle

19. Citric Acid Production Figure 9–6 The Krebs Cycle Mitochondrion

20. 3 Stages make up Cellular Respiration Electron Transport – uses high-energy electrons from the Krebs cycle to convert ADP into ATP.  In eukaryotes it’s composed of carrier proteins located in the mitochondria.  In prokaryotes the same chain is in the cell membrane where energy is used to move H+ ions through ATP synthase.  ATP synthase – protein sphere that spins, adding a phosphate to ADP creating ATP.  No O 2 – product is glycolysis.  Yes O 2 – more ATP is extracted.

21. The Electron Transport Chain

23. Figure 9–7 Electron Transport Chain Electron Transport Hydrogen Ion Movement ATP Production ATP synthase Channel Inner Membrane Matrix Intermembrane Space Mitochondrion

24. Cellular Respiration Glycolysis + Krebs + Electron Transport = 36 ATP / glucose molecules.

25. The Human Body Contains small amounts of ATP. When the body needs energy fast, muscle cells produce ATP by Lactic Acid Fermentation. For long-term needs, the body must use cellular respiration.

26. Comparing Photosynthesis & Cellular Respiration Energy flows in Photosynthesis Cellular Respiration takes place in the opposite direction.  Photosynthesis – removes CO 2 & puts O 2 back into air.  Cellular Respiration – removes O 2 & puts CO 2 back into air.

27. Comparing Photosynthesis & Cellular Respiration Cellular Respiration 6O2 + C 6 H 12 O 6 → 6CO 2 + 6H 2 O + Energy Photosynthesis 6CO 2 + 6H 2 O + light→C 6 H 12 O 6 + 6O 2