1. Part 2: Photosynthesis overview, chloroplast structure & pigments
Unit 4 Cell Energetics!
Part 2: Photosynthesis overview, chloroplast structure & pigments

2. Learning Targets
Identify the inputs and outputs and location of the light reactions (LDR) and Calvin Cycle (LIR).
Describe the purpose of chlorophyll and accessory pigments.
7. Compare and contrast the structure and function of mitochondria and chloroplasts.

3. Chloroplast structure
Be able to ID the following:
Inner membrane*
Outer membrane*
Granum
Thylakoid
Stroma
*supports the endosymbiotic theory

4. Endosymbiotic Theory?
A larger cell (pre-eukaryote) engulfed a smaller prokaryote  the smaller one provided energy  instead of “eating” the small bacteria they became bffs
Other evidence that supports this
Chloroplasts & mitochondria have their OWN DNA!!! 

6. Chloroplasts… Found in mesophyll
1 mesophyll cell may have 30 chloroplasts! (remember the elodea?)

7. Photosynthesis Overview
Light reactions (LDR)
Depend on light
Occur in Thylakoid Membrane
Light Independent reactions (LIR)
Does NOT need light
Occurs in the Stroma

8. Location, location, location
Learning check:
Light Dependent Reaction occurs…where?
Light Independent reaction occurs…where?

9. Photosynthesis background
Pigments
this is what absorbs the light energy from the sun it excites electrons making it unstable
Photosystems (PS 1 & PS 2)
Made of pigments & proteins

10. Pigments Chlorophyll Chlorophyll a  main pigment  blue-green
Chlorophyll b  accessory pigment  yellow-green
Other accessory pigments  absorb different wavelengths of light
Carotenoids  yellow-orange
Xanthophyll yellow
Rhodophyll  red
Fucoxanthin  brown
Why are plants green?
Why are plants changing color?

11. Photosystems Consist of There are 2
Pigments (chlorophyll b, carotenoids & xanthophyll)
Proteins!
There are 2
Photosystem 1
The last photosystem in the Light Dependent Reaction (LDR)
Photosystem 2
The FIRST photosystem in the LDR
Photosystem 2 comes first, but has the #2 after it because we discovered it second…

12. Photosystems Process:
Photon (light energy) absorbed by pigments  excites e- in pigment e- jump to higher levels  eventually reaches the reaction center (chlorophyll a)  transfers energy to the reaction center  passed back down through an ETC in LDR

13. Learning Check Where does the Light Dependent Reaction occur?
2. Where does the Light Independent reaction occur?
What factors could affect the process of photosynthesis?
What do pigments do (purpose & function)?
What happens in a photosystem?
What is a photosystem?
What is the relationship between PS1 & PS2 (similarities, order, help each other?)