1. Cell Energy

2. Main Topics
Photosynthesis
Cellular Respiration

3. Objectives
Know the roles of photosynthesis and cell respiration in the ecosystem
Describe reactants and products in both photosynthesis and cellular respiration
Compare and contrast systems in plants and animals for nutrient absorption, hormone response, and gas exchange

4. Vocab Photosynthesis Cellular Respiration Autotroph Heterotroph
Aerobic
Anaerobic

5. How do organisms obtain and use energy?

6. All cells use chemical energy carried by ATP

8. Autotroph- can make their own food
Ex: plants, algae
Heterotroph- cannot make their own food
Must eat others for food
Ex: animals, humans

9. Photosynthesis
A process that captures energy from sunlight to make sugars that store chemical energy.
Sun’s energy >>> Chemical energy (sugar)
Takes place in the chloroplast
Note: energy for almost all organisms begins as sunlight.

11. Photosynthesis

12. Factors that affect photosynthesis
Water
Temperature
Light intensity

13. Chlorophyll
A molecule in chloroplasts that absorbs some of the energy in visible light
Two main types of chlorophyll (a and b)
Absorb mostly red and blue wavelengths of light
Reflect green wavelength of light

14. Chloroplast

15. Chloroplast overview
Two main parts of the chloroplast needed for photosynthesis are the grana and the stroma.
Grana (granum)- stacks of coin-shaped compartments called thylakoids.
Stroma- fluid that surrounds the grana inside a chloroplast.
Thylakoids- membranes of thylakoids contain chlorophyll.

16. Photosynthesis in detail
Light-dependent reactions
Capture energy from sunlight
Take place in membrane of thylakoids
Water and sunlight needed
Light-independent reactions
Also called the Calvin Cycle
Uses energy from light-dependent reactions to make sugars
Take place in the stroma
Carbon dioxide needed

17. Light-dependent reactions
Water molecules are broken down
Oxygen molecules are released
Energy carried along thylakoid is transferred to ATP

18. Light-independent reactions Calvin cycle
Carbon dioxide is added
Energy from light-dependent reactions is used
Sugar is formed (usually glucose)

19. Photosynthesis video

20. Plant anatomy (nutrient absorption)

21. Plant anatomy (gas exchange)

22. Cellular Respiration
Process that releases chemical energy from sugars and other carbon-based molecules to make ATP when oxygen is present.
Aerobic process- it requires oxygen
Takes place in the mitochondria

25. Mitochondria

26. 3 steps of cell respiration
Glycolysis
Krebs Cycle
Electron Transport

27. Glycolysis
Splits glucose into two three-carbon molecules and makes two molecules of ATP
Anaerobic process- does not require oxygen
Takes place in the cell’s cytoplasm (not in the mitochondria)

28. Krebs cycle
Takes place in the interior space, or matrix, of the mitochondrion
Uses the three-carbon molecules from glycolysis
Small number of ATP molecules are made
Carbon dioxide given off as waste
Energy is transferred to the electron transport chain

29. Electron transport
Takes place in the inner membrane of the mitochondrion
Energy from the Krebs cycle is transferred to the inner membrane
Oxygen enters the process
Large number of ATP molecules are made
Water and heat are given off as waste

31. Cellular Respiration
Up to 38 ATP molecules are made from the breakdown of 1 glucose molecule
Used when oxygen is present

32. Fermentation Does not make ATP, but it allows glycolysis to continue
Used when oxygen is not present
Produces lactic acid, which causes your muscles to burn during hard exercise

33. Crash Course: Cell Respiration