1. Photosynthesis
6 October 2014

2. Photosynthesis: process that captures energy from sunlight to make sugars that store energy.

3. Chlorophyll: green pigment that absorbs sunlight
Chlorophyll: green pigment that absorbs sunlight. Chlorophyll absorbs mostly blue and red light, but reflects green.

4. Chloroplasts: membrane-bound organelle’s where photosynthesis takes place. Thylakoids are located within chloroplast.

5. Thylakoids: coin-shaped, membrane-bound compartments that contain light-absorbing molecules.

6. If a stack of pancakes is a granum, each pancake would be a thylakoid.

7. Light-Dependent Reactions capture energy from sunlight to make ATP and NADPH.

8. Light-Independent Reaction, aka The Calvin Cycle, aka The Dark Reactions, uses ATP and NADPH to make sugar.

9. Photosystem II : Group of molecules that absorb light and transfer it to electrons.

10. Photosystem II
Step 1) Chlorophyll loses 2 electrons to the electron transport chain (ETC), which is a series of proteins in the thylakoids.

11. Photosystem II
Step 2) Water is split into O2 , 2 electrons, and 2 Hydrogen ions. The 2 electrons from Hydrogen replace the 2 lost from chlorophyll.

12. Photosystem II
Step 3) The electrons in the ETC provides energy to pump Hydrogen ions into the thylakoids.

13. Reduction vs. Oxidation
1. If electrons are added to a molecule, then that molecule is reduced. If you add NEGATIVE charges to something, you are REDUCING it. Electrons have negative charges… 2. If electrons leave a molecule, then that molecule is oxidized.

15. NADP+ (Nicotinamide Adenine Dinucleotide Phosphate) acts like ADP in Photosynthesis. NADPH : reduced form of NADP+ that acts like ATP in photosynthesis.

17. Photosystem I : Group of molecules that also absorb energy and add it to electrons from photosystem II.

18. Photosystem I
4) Energy from sun is absorbed and added to electrons from PSII.

19. Photosystem I
5) NADPH production. Some of the energized electrons from PSII are added to NADP+ which turns NADP+ into NADPH.

20. Ion Formation

21. Ion Formation

22. Ion Formation

23. Ion Formation

24. Photosystem I
5) Hydrogen Ion Diffusion. The hydrogen ions diffuse through a protein channel in the thylakoid membranes.

25. Photosystem I
6) ATP is produced. The flow of ions through the protein channel provides the energy for ATP synthase to add phosphate groups to ADP.

29. The Calvin Cycle (light independent)
The Calvin Cycle uses energy from ATP and NADPH to make sugars.

30. The Calvin Cycle uses energy from ATP and NADPH to make sugars using Carbon from CO2. During The Calvin Cycle, 2 three-carbon molecules are used to make 1 six-carbon molecule called GLUCOSE. ATP and NADPH are converted into ADP and NADP+ which return to the light-dependent reactions. +