1. Chapter 9 Energy in a Cell

2. Section 9.1 The Need for Energy
Explain why organisms need a supply of energy.
Describe how energy is stored and released by ATP.

3. ATP: The Energy unit of the Cell
CH2 H OH N C HC
NH2
Adenine
Ribose
Phosphate groups - CH
ATP (adenosine triphosphate,三磷酸腺苷）

4. Cell Energy use in Active Transport

5. Energy is released from ATP (-30.54 kJ/mol)
When the terminal phosphate bond is broken

8. Section 9.2 Photosynthesis: Trapping the Sun’s Energy
Relate the structure of chloroplasts to the events in photosynthesis.
Describe light-dependent reactions.
Explain the reactions and products of the lightindependent Calvin cycle.

9. Trapping Energy from Sunlight
The process that uses the sun’s energy to make simple sugars is called photosynthesis(光合作用).
(P 225)
6 CO H2O + Light energy  C6H12O6 + 6 O2 + 6 H2 O

10. Leaf cross section
Vein
Mesophyll
Stomata
CO2 O2

11. P 184

12. The Light-Dependent reactions （光反应）
Reflected
Chloroplast
Absorbed
light
Granum
Transmitted
Pigments- light absorbing molecules
Chlorophyll a (main pigment in photosystem 1)
Chlorophyll b (main pigment in photosystem 2)

13. The Light-Dependent reactions
Photolysis

14. 3H+= 1 ATP
Chemiosmosis:
Movement of chemicals across a selectively- permeable membrane

15. H2O CO2 [CH2O] O2 (sugar) Light NADP  ADP + P CALVIN LIGHT REACTIONS
CYCLE
Chloroplast
[CH2O]
(sugar)
NADPH
NADP 
ADP
+ P O2
ATP

16. The Light-Independent reactions

17. Final Numbers Use Produce Light-Dependent Reactions Sunlight NADPH H2O
ATP O2
Use
Produce
Light-Independent Reactions
(Calvin Cycle)
NADPH
RuBP
ATP
PGAL (Which form sugars)
CO2
NADP+/ADP/Pi

20. P 242

21. Section9.3 Getting Energy to Make ATP
Compare and contrast cellular respiration and fermentation.
Explain how cells obtain energy from cellular respiration.

22. Cellular Respiration (p 231)
The process by which mitochondria break down food molecules to produce ATP is called cellular respiration(细胞呼吸).
C6H12O6 + 6O2 = 6CO2 + 6H2O + ATP

24. Oxidative phosphorylation: electron transport and chemiosmosis
Cellular Respiration
Electrons
carried
via NADH
Glycolsis
Glucose
Pyruvate
ATP
Substrate-level
phosphorylation
Electrons carried
via NADH and
FADH2
Citric acid cycle
Oxidative phosphorylation: electron transport and chemiosmosis
Oxidative
Mitochondrion
Cytosol
Aerobic Reactions
Anaerobic Reactions

25. Cellular Respiration Glycolysis (糖酵解)
Total
NADH 2
FADH2
ATP
-2+4= 2
Glycolysis (糖酵解)
in the cytoplasm，break down glucose, into two molecules of pyruvic acid a (3-C)
is anaerobic—no oxygen is required.
2 ATP go in, 4 come out; Net Gain of 2 ATP
Also produces 2 NADH

26. Cellular Respiration
Total
NADH
2+2= 4
FADH2
ATP 2
CO2

27. Krebs Cycle
Total
NADH
4+6= 10
FADH2 2
ATP
2+2= 4
CO2
2+4= 6

28. Electron Transport Chain
Total
NADH
-10
FADH2 -2
ATP
4+34= 38
CO2 6
H2O
（电子传递链）
2H+ = 1 ATP

29. Final Numbers…

30. Cellular Respiration

32. Fermentation (发酵)
In the absence of oxygen，cells can still produce ATP through fermentation
There are two major types of fermentation: lactic acid fermentation （乳酸发酵）
and alcoholic fermentation（酒精发酵）.

34. Glucose CYTOSOL Pyruvate Ethanol or lactate
No O2 present
Fermentation
O2 present
Cellular respiration
Ethanol or
lactate
Acetyl CoA
MITOCHONDRION
Citric
acid
cycle

35. Lactic Acid Fermentation
Fermentation allows constant energy supply during exercise
Lactic acid can not be changed back into pyruvic acid in the cells
Liver has enzymes designed to convert lactic acid
Lactic acid builds up too fast and changes the pH of muscle cells
Change in pH slows performance and weakens the muscle cells

36. Alcohol Fermentation

37. P 235

38. Comparing Photosynthesis and Cellular Respiration

42. That’s all