1. Chapter 9
Energy in a Cell

2. Adenosine Triphosphate
Main molecule of energy in all living things
Energy is stored in the bonds that attach the phosphate groups
Energy is released when those bonds are broken

4. Why do we need energy? To perform all of our life functions
Ex] moving, digesting food, breathing, moving substances through the organism

5. Photosynthesis

6. Process of converting sunlight into stored energy
Occurs in the chloroplast
6CO2 + 6H2O  C6H12O6 + 6O2

7. Chloroplast

8. Light-Dependent Reactions
Occurs in the thylakoid membrane of the chloroplast
Sunlight energizes electrons
Enter into a chain to transfer the energy
When they reach the end of the chain, remaining energy is transferred to a molecule called NADPH and moved to the next cycle.

9. Light-Independent Reactions
Also called the Calvin cycle
Occurs in the stroma of the chloroplast
Uses carbon dioxide to make sugar

10. Who performs photosynthesis?
Plants
Some protists
Some bacteria

11. Cellular Respiration
Process of changing food into energy

12. Glycolysis Occurs in the cytoplasm Produces 4 ATP molecules
2 ATP molecules are needed to start glycolysis
Net gain after glycolysis:
2 ATP

13. Anaerobic vs. Aerobic Respiration
If oxygen is available – aerobic respiration
If oxygen is not available – anaerobic respiration
Cells prefer aerobic respiration – WHY?

14. Aerobic Respiration Occurs in the mitochondria
Krebs cycle produces 2 ATP
Electron transport chain produces 32 ATP
From one molecule of glucose, 38 ATP are produced
Net gain = 36 ATP
C6H12O6 + 6O2  6CO2 + 6H2O

15. Anaerobic Respiration
Produces 2 ATP
Net gain of 4 ATP
Lactic acid and alcoholic fermentation

16. Lactic Acid Fermentation
Occurs in human muscle cells
Produces burning sensation

17. Alcoholic Fermentation
Produces carbon dioxide
Important in bread and alcohol production

18. Who performs cellular respiration?
EVERYONE!!!