1. Chapter 9 Notes
Cellular Respiration

2. 9-1 Chemical Pathways All living organisms need food to survive.
Food provides living things with the chemical building blocks they need to grow and reproduce.

3. 9-1 Chemical Pathways
1 gram of glucose releases 3811 calories of heat energy
Calorie (c): the amount of energy needed to raise the temperature of 1 gram of water 1 Celsius degree
The calories on food labels (C) are kilocalories or 1000 calories

4. 9-1 Chemical Pathways
Cells gradually release energy from glucose and other food compounds.
Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen.
- 3 parts: glycolysis, the Krebs cycle, and the electron transport chain

5. Electron Transport Chain
Electrons carried in NADH
Pyruvic acid
Electrons carried in NADH and FADH2
Glucose
Glycolysis
Krebs Cycle
Electron Transport Chain
Cytoplasm
Mitochondrion

6. 9-1 Chemical Pathways Equation for Cellular Respiration
6O2 + C6H12O6  6CO2 + 6 H2O + Energy
oxygen+glucose carbon+water+energy
dioxide

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

8. 9-1 Chemical Pathways
The first set of chemical reactions in cellular respiration is glycolysis.
Glycolysis is the process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound

9. 9-1 Chemical Pathways Net results of glycolysis
- 2 molecules of ATP are gained
- 2 molecules of NADH are gained
- 2 molecules of pyruvic acid (3C) are formed from 1 glucose molecule

10. 9-1 Chemical Pathways
2 ATP
2 ADP
4 ADP
4 ATP
Glucose
2 Pyruvic
acid

11. 9-1 Chemical Pathways
When oxygen is present in the cell, glycolysis is followed by the Krebs cycle.
If there is no oxygen present, glycolysis is followed by fermentation.
Fermentation releases energy from food molecules in the absence of oxygen

12. 9-1 Chemical Pathways
Because fermentation does not require oxygen it is said to be anaerobic.
The two main types of fermentation are alcoholic fermentation and lactic acid fermentation

13. 9-1 Chemical Pathways

14. 9-1 Chemical Pathways

15. 9-1 Chemical Pathways
Alcoholic fermentation is used mainly by plants and yeasts
- alcohol is the product
Lactic acid fermentation occurs in muscle cells when the body cannot supply enough oxygen to the tissues
- lactic acid is the product

16. Section Quiz The raw materials required for cellular respiration are
carbon dioxide and oxygen.
glucose and water.
glucose and oxygen.
carbon dioxide and water.

17. Section Quiz Glycolysis occurs in the mitochondria. cytoplasm.
nucleus.
chloroplasts.

18. Section Quiz The net gain of ATP molecules after glycolysis is
3 pyruvic acid molecules.
4 pyruvic acid molecules

19. Section Quiz
Fermentation releases energy from food molecules in the absence of
oxygen.
glucose.
NADH.
alcohol.

20. Section Quiz The first step in fermentation is always
lactic acid production.
the Krebs cycle.
glycolysis.
alcohol production.

21. 9-2 The Krebs Cycle and Electron Transport
Oxygen is used for the final steps of cellular respiration. Because the pathway requires oxygen, it is said to be aerobic.
In the presence of O2, pyruvic acid passes on to the second stage of cellular respiration, the Krebs cycle

22. 9-2 The Krebs Cycle and Electron Transport
During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
Net result of the Krebs cycle
- 2 molecules of pyruvic acid enter
- 8 molecules of NADH are gained
- 2 molecules of FADH2 are gained
- 2 molecules of ATP are gained

23. Mitochondrion
Citric Acid Production

24. 9-2 The Krebs Cycle and Electron Transport
From glycolysis and the Krebs cycle high energy electron carriers, NADH and FADH2, are produced. The electrons are then passed to the electron transport chain.
The electron transport chain uses high energy electrons to convert ADP to ATP.
ETC Movie pt 1
ETC Movie pt 2

25. 9-2 The Krebs Cycle and Electron Transport

26. 9-2 The Krebs Cycle and Electron Transport

27. 9-2 The Krebs Cycle and Electron Transport

28. 9-2 The Krebs Cycle and Electron Transport
ATP synthase

29. 9-2 The Krebs Cycle and Electron Transport
Channel
ATP synthase
ATP

30. 9-2 The Krebs Cycle and Electron Transport
Each NADH make 3 ATP while each FADH2 makes 2 ATP
1 glucose molecule can then make 38 total ATP ( 4 ATP, 10 NADH  30 ATP, 2 FADH2  4 ATP)
Cellular Respiration Animation

31. Section Quiz The Krebs cycle breaks pyruvic acid down into oxygen.
NADH.
carbon dioxide.
alcohol.

32. Section Quiz
In eukaryotes, the electron transport chain is located in the
cell membrane.
inner mitochondrial membrane.
cytoplasm.
outer mitochondrial membrane.

33. Section Quiz To generate energy over long periods, the body must use
stored ATP.
lactic acid fermentation.
cellular respiration.
glycolysis.

34. Section Quiz
Which statement correctly describes photosynthesis and cellular respiration?
Photosynthesis releases energy, while cellular respiration stores energy.
Photosynthesis and cellular respiration use the same raw materials.
Cellular respiration releases energy, while photosynthesis stores energy.
Cellular respiration and photosynthesis produce the same products.