1. PHOTOSYNTHESIS

2. I. Autotrophs and Heterotrophs
Energy for living things comes from the SUN
Autotrophs- make their own food
Ex: plants, some bacteria, protists

3. Heterotrophs- obtain it from the foods they consume
Ex: animals, some bacteria,
protozoans (and even
fungi!)

4. Sooo… food is either MADE through photosynthesis or OBTAINED through consumption

5. Think about the Location of Photosynthesis…

6. II. Location of Photosynthesis Which tissues contain chloroplasts?

7. Other Important Parts Xylem: transports H2O
Stoma: pore that allows gases to enter and exit

8. III. CHLOROPLAST STRUCTURE
Double-membrane structure
Internal Organization
1. Thylakoids:
a. These have clusters of chlorophyll and other pigments
2. Stroma: Fluid surrounding thylakoids

9. IV. Light & Pigments
A. Sunlight is “white” but contains mixtures of visible wavelengths
B. Plants gather sun’s energy using light-absorbing molecules called PIGMENTS

10. V. Plant Pigments MAJOR MINOR Chlorophyll a Chlorophyll b Xanthophyll
Absorbs all colors of light
except green
Plays major role in light
reactions of photosynthesis
Chlorophyll b
Yellow-green
Xanthophyll
In carotenoid family
Yellow
Carotene
Red & orange pigments
MAJOR
MINOR

11. B. Visible energy spans
wavelengths of approx. nm
C. It is part of the
electromagnetic spectrum

12. Green is NOT absorbed!
Plant pigments absorb different wavelengths of energy- which wavelength is the LEAST absorbed?

13. 1. Leaves absorb blue-violet & red-orange light very well 2
1. Leaves absorb blue-violet & red-orange light very well 2. Green light is REFLECTED which is why plants look green!

14. VI. PHOTOSYNTHESIS Inputs: Light, carbon dioxide, & water
Outputs: sugar and oxygen

15. VI. Photosynthesis Has Two Parts:
Light Reaction
Calvin Cycle

16. VII. Light Reaction Chlorophyll capture light energy in chloroplast
This splits H2O into oxygen and hydrogen
Oxygen is a "waste product" & escapes to the atmosphere
Energy from the reaction is used in the next stage.

17. B. ATP and NADP are recycled back into
the system
C. Light reaction is charging up the
“battery” needed to make
sugars in Calvin Cycle

18. IX. Calvin Cycle Does NOT use light at all
Uses energy from Light Cycle to convert CO2 into glucose

19. Reactants:
Products:

20. Two Processes
Calvin Cycle
Light Reaction

21. Factors Affecting Photosynthesis
Shortage of raw materials
Temperature
Light intensity