1. PHOTOSYNTHESIS

2. Photosynthesis
Carbon dioxide (CO2) requiring process that uses light energy and water (H2O) to produce glucose.
sun+6CO H2O  C6H12O O2
glucose
SUN
photons

3. Where does photosynthesis take place?
Question:
Where does photosynthesis take place?

4. Plants Autotrophs – produce their own food (glucose)
Process called photosynthesis
Mainly occurs in the leaves:
a. stoma - pores
b. mesophyll cells
Mesophyll
Cell
Chloroplast
Stoma

5. Stomata (stoma)
Pores in a plant’s cuticle through which water vapor and gases (CO2 & O2) are exchanged between the plant and the atmosphere.
Guard Cell
Oxygen
(O2)
Stoma
Carbon Dioxide
(CO2)
Found on the underside of leaves

6. Mesophyll Cell of Leaf Photosynthesis occurs in these cells! Nucleus
Cell Wall
Chloroplast
Central Vacuole
Photosynthesis occurs in these cells!

7. Chloroplast Organelle where photosynthesis takes place.
Stroma
Outer Membrane
Thylakoid
Granum
Inner Membrane
Thylakoid stacks are connected together

8. Grana make up the inner membrane
Thylakoid
Thylakoid Membrane
Granum
Thylakoid Space
Grana make up the inner membrane

9. Question:
Why are plants green?

10. Chlorophyll Molecules
Located in the thylakoid membranes
Chlorophyll pigments harvest energy (photons) by absorbing certain wavelengths (blue-420 nm and red-660 nm are most important)
Plants are green because the green pigment is reflected, not absorbed.

11. Factors Affecting the Rate of Photosynthesis
Temperature: temp. must stay between 0-35 C, or else the enzymes denature
Water availability: photosynthesis will slow down if there is no water
Light Intensity: plants reach maximum intensities and then photo. will level off

12. Why do cells use sunlight for energy?
Question:
Why do cells use sunlight for energy?

13. Energy for Life on Earth
Sunlight is the ULTIMATE energy for all life on Earth
Plants store energy in the chemical bonds of sugars
Chemical energy is released as ATP during cellular respiration