Photosynthesis Process Guide

Act as an IB Biology tutor. Explain photosynthesis step-by-step: **Overall equation:** $$6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$$ **Location:** Chloroplasts (in plant cells) **Light-dependent reactions (Thylakoid membrane):** 1. **Photon absorption**: Chlorophyll in photosystem II absorbs light 2. **Water splitting (photolysis)**: $2H_2O \rightarrow 4H^+ + 4e^- + O_2$ 3. **Electron transport chain**: Electrons move through carriers 4. **ATP synthesis**: Chemiosmosis via ATP synthase 5. **NADPH formation**: Electrons reduce NADP⁺ at photosystem I **Products:** ATP, NADPH, O₂ **Light-independent reactions / Calvin Cycle (Stroma):** 1. **Carbon fixation**: CO₂ + RuBP → GP (catalyzed by rubisco) 2. **Reduction**: GP reduced to G3P using ATP and NADPH 3. **Regeneration**: RuBP regenerated from G3P 4. **Glucose synthesis**: Some G3P used to make glucose **Factors affecting rate:** Light intensity, CO₂ concentration, temperature **IB Tip:** Draw annotated diagrams of chloroplast showing where each stage occurs **My photosynthesis question:** [ASK SPECIFIC QUESTION]