1. Photosynthesis

2. -Primarily in chloroplasts of plants -Reactions occur inside structures within the chloroplasts called thylakoids and the stroma.

3. Chloroplast Single thylakoid Granum Stroma

4. Overall Reaction of Photosynthesis Reactants: carbon dioxide, water, and energy (sun) Products: glucose and oxygen 6CO 2 + 6H 2 O + Energy  C 6 H 12 O 6 + 6O 2

5. Light Reactions Function: -Energy from the sun is absorbed by chlorophyll located inside the thylakoids. -The light energy is transferred from the chlorophyll to NADP + to form NADPH. This occurs in a series of reactions called the electron transport chain (ETC) across the thylakoid membrane. -ATP is formed from ADP by chemiosmosis across the thylakoid membrane. (ADP adds a P group with the help of the protein ATP Synthase.) Location: chlorophyll & thylakoid membrane Reactants: H 2 O, energy (sun) ADP, and NADP +. Products: oxygen, ATP, and NADPH.

6. Photosynthesis Light H2OH2O O2O2 CO 2 Sugars NADP + ADP + P Light- dependent reactions Calvin cycle

7. Calvin Cycle (Dark Reactions) Function: -No sunlight is needed. -Plants use the energy within ATP and NADPH to build organic compounds (glucose) which are sources of nutrients for the plant. Location: stroma of the chloroplast Reactants: CO 2 (from air), ATP and NADPH Products: Organic Compounds (Glucose)

8. Photosynthesis Light H2OH2O O2O2 CO 2 Sugars NADP + ADP + P Light- dependent reactions Calvin cycle

9. Photosynthesis The two sets of photosynthetic reactions work together. – The light-dependent reactions trap sunlight energy in chemical form. – The light-independent reactions use that chemical energy to produce stable, high-energy sugars from carbon dioxide and water.

10. Alternative Biochemical Pathways C 4 Pathway – Plants in hot, dry climates. Try to prevent water loss. Water loss occurs through the stomata. (Passageway for O 2 & CO 2 entering and leaving the plant.) CAM Pathway – open stomata only at night. C 3, C 4 & CAM pathway plants also differ by the initial product of carbon fixation.

11. Factors affecting the Rate of Photosynthesis: Light Intensity Amount of CO 2 Temperature