1. Photosynthesis and plant cells Photosynthesis and plant cells

2. Photosynthesis A definition: Photosynthesis is the process a plant uses to make food and grow.

3. Four things are needed for photosynthesis: Travels up from the roots WATER CARBON DIOXIDE Enters the leaf through small holes on the underneath SUNLIGHT Gives the plant energy CHLOROPHYLL Where the chemical reactions happen

4. The word and chemical equations for photosynthesis: Carbon dioxide + water glucose + oxygen 6CO 2 + 6H 2 0C 6 H 12 O 6 + 6O 2 Sunlight Chlorophyll Sunlight Chlorophyll

5. Four factors affect photosynthesis: 1.More light = Faster rate of photosynthesis. 2.Water – if Lack of water slows photosynthesis down. 3.Temperature – Hot temperatures slows photosynthesis down. 4.CO 2 – more carbon dioxide, photosynthesis happens faster.

6. Leaf Stomata (plural Stoma) Microscopic “mouths” in leaves that let CO2 in and water & O2 out. Stomata can close by swelling the “lips” or guard cells. Why would they need to close?

7. Photosynthesis happens in the “palisade” cells in the leaf: Palisade cells

8. Close up on a palisade cell: Cell wall Cell membrane Nucleus Large vacuole Cytoplasm Chloroplasts (containing chlorophyll)

9. How do Plant Roots Work? Paper towels can absorb more water if they have larger surface area! Roots also work by using a large surface area. What makes the water move into the roots? Diffusion!

10. Plant roots are made of “root hair cells” which have a large surface area and a thin cell membrane to help absorb minerals and water: Thin cell membrane Large surface area

11. Plant growth Plants grow using food they make through photosynthesis. So what else do they need? Plants also need three important minerals to keep healthy. They absorb these through their roots.

12. 3 types of nutrients: 1.Nitrates – used to make proteins 2.Phosphates –to help photosynthesis and respiration 3.Potassium – helps build enzymes the plant needs