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 + C6H12O6 → 6CO2 + 6H2O + Energy
oxygen + glucose → carbon dioxide + water + energy

5. Aerobic Respiration

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

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

8. Figure 9–2 Cellular Respiration: An Overview
Section 9-1
Mitochondrion
Electrons carried in NADH
Electrons carried in NADH and FADH2
Pyruvic acid
Glucose
Electron Transport Chain
Krebs Cycle
Glycolysis
Mitochondrion
Cytoplasm

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.
O2 present - it is followed by the Kreb Cycle & the electron transport chain.
O2 not present (anaerobic) - it is followed by fermentation.

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

11. Glycolysis http://highered. mcgraw-hill

12. Fermentation
Fermentation – releases energy in food & converts NADH back into NAD+ keeping the supply of ATP constant.
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 O2 to the tissues; without oxygen, the body isn’t able to produce the ATP required. Buildup causes pain & soreness.

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

14. Section 9-2
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?

15. Electron Transport Chain
Section 9-2
Flowchart
Cellular Respiration
Glucose (C6H1206) +
Oxygen (02)
Glycolysis
Krebs Cycle
Electron Transport Chain
Carbon
Dioxide
(CO2) +
Water
(H2O)

16. 3 Stages make up Cellular Respiration
Kreb Cycle – requires O2 (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 CO2 which is released into the air.
NAD+ is changed to NADH & FAD is changed to FADH2 which carry high-energy electrons to the electron transport chain.

17. The Krebs Cycle http://highered. mcgraw-hill

18. The Krebs Cycle

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

21. The Electron Transport Chain

22. The Electron Transport Chain

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

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 CO2 & puts O2 back into air.
Cellular Respiration – removes O2 & puts CO2 back into air.

27. Comparing Photosynthesis & Cellular Respiration
6O2 + C6H12O6 → 6CO2 + 6H2O + Energy
Photosynthesis
6CO2 + 6H2O + light→C6H12O6 + 6O2