Structured Study Guide — Photosynthesis 1. Definition Photosynthesis is the process by which plants convert light energy into chemical energy. Plants mainly perform photosynthesis in their leaves, inside structures called chloroplasts. 2. Essential Elements Plants need: * Light energy * Water * Carbon dioxide * Chlorophyll The main products are: * Glucose * Oxygen 3. Simplified Equation Carbon dioxide + Water + Light → Glucose + Oxygen 4. Main Stages **Light-dependent reactions** Light is absorbed by chlorophyll and used to produce energy. **Carbon fixation** The plant uses carbon dioxide and the energy produced during the first stage to create glucose. Key Concepts * Chloroplast: structure where photosynthesis occurs. * Chlorophyll: pigment that absorbs light. * Glucose: sugar used by the plant as an energy source. * Carbon dioxide: gas absorbed from the atmosphere. * Oxygen: released as a by-product. Quick Summary 1. Photosynthesis allows plants to produce energy-rich glucose. 2. It mainly occurs in the leaves. 3. Chlorophyll absorbs light energy. 4. Water is absorbed by the roots. 5. Carbon dioxide enters through the leaves. 6. Glucose is produced. 7. Oxygen is released into the atmosphere. Revision Questions 1. What is the main purpose of photosynthesis? 2. Where does photosynthesis occur in plant cells? 3. What role does chlorophyll play? 4. Name the three main elements required for photosynthesis. 5. True or false: Oxygen is consumed during photosynthesis. 6. What is glucose used for by plants? Exam Focus Prioritize the photosynthesis equation, the role of chlorophyll and the inputs and outputs of the process. These are the concepts most likely to be required when explaining the mechanism.