KS3 & KS4 science curriculum

This unit builds on pupils’ prior learning from Coordination and control: maintaining a constant internal environment, where they explored how organisms regulate internal processes. It deepens their understanding by examining the factors that affect the rate of photosynthesis, such as light, temperature, and carbon dioxide. As the final unit in the big question, What are living things and what are they made of?, it reinforces pupils’ knowledge of how living organisms use energy to sustain life.

1. Factors affecting the rate of photosynthesis
2. The effect of light intensity on rate of photosynthesis in pondweed: plan
3. The effect of light intensity on rate of photosynthesis in pondweed: practical
4. The effect of light intensity on rate of photosynthesis in pondweed: evaluation
5. Light intensity and the inverse square law
6. Photosynthesis and limiting factors

• Producers, including plants, use a chemical process called photosynthesis to make their own food in the form of glucose (a type of carbohydrate).
• A balanced symbol equation to summarise the chemical reactants and products of the process of photosynthesis.
• Plant leaves are adapted for photosynthesis; they have stomata for gas exchange, to absorb carbon dioxide and release waste oxygen.
• Photosynthesis takes place in chloroplasts in cells that make up the aerial parts of plants.
• Chloroplasts contain a pigment called chlorophyll that absorbs light.
• Light is not a chemical reactant, but transfers energy to chlorophyll to enable photosynthesis to take place.
• Enzymes are the catalysts for many chemical reactions in living organisms.
• Photosynthesis involves many chemical reactions, catalysed by enzymes.
• Enzymes work best in optimum conditions and less well when conditions change away from the optimum.