1. Intro to Pigments & Photosynthesis

2. But first, a review. What is the point of cell respiration?
These words all relate to cell respiration. How so?
Catabolic
Chemiosmosis
Cytoplasm
Cristae
Redox reactions

3. What determines the direction taken?
Where does it happen?
Other products made?
Where does it happen? What is it made of?
Proton motive force
- Where does it happen?
What is the end product?
Krebs Cycle
ETC
Glycolysis
What determines the direction taken?
Fermentation
Where does it happen?
Two kinds?
-What’s the point?

4. Photosynthesis Essentially the reverse of respiration
Capturing free energy
Anabolic
CO2 eventually reduced to sugar
Endergonic
Makes O2 from splitting of water

5. Obtaining Energy Autotroph vs. heterotroph
Photoautotroph- photosynthesis
Chemoautotroph- chemosynthesis

8. Chlorophyll Green pigment Embedded in thylakoid membrane
Absorbs various wavelengths of light

9. Wavelengths of Light Red: Long wavelength. Around 700 nm. Violet:
Shorter wavelength, higher energy
Longer wavelength, lower energy
Red:
Long wavelength. Around 700 nm.
Violet:
Short wavelength. Around 400 nm.

10. Pigments for Photosynthesis
Chlorophyll a (P680 and P700)
Chlorophyll b
Carotenoids
Xanthophyll
Each pigment has an absorption spectrum

11. Colors that are NOT absorbed are reflected- that’s the color we see

12. Chlorophyll a Best absorbs around 430 and 680 nm (violet/blue and red)
Appears blue- green

13. Chlorophyll b
Best absorbs around 450 and 640 nm (violet/blue and red/orange)
Appears olive green

14. Carotenoids?
Best absorbs around
Appears

15. Food for thought
So…green light is actually pretty terrible for photosynthesis.
If you want to help your plants, give them more…?
Fall colors (other pigments) appear when chlorophyll no longer produced

16. earthguide. uscd. edu: Absorption of EM Radiation http://earthguide
Protons, electrons and the hydrogen atom
Electron absorbs radiation of a specific wavelength
Allows it to jump to a higher energy level- it’s excited
Eventually emits the same amount of energy and “falls” to its “ground state”
Measured with a spectrophotometer