Photosynthesis

• Photosynthesis converts energy from the sun into chemical energy for the food chains.
• Photosynthesis keeps the levels of oxygen and carbon dioxide in the atmosphere in balance – without it we would very quickly run out of oxygen.
• Thin:Provides a short distance for carbon dioxide to move by diffusion into the leaf
• Large surface area: It can absorb a lot of light
• Stomata Small holes in the underside of the leaf that allow carbon dioxide and oxygen to move in and out of the leaf by diffusion
• Guard cells: These are two specialised plant cells which control the opening and closing of stomata
• It's top surface is protected from water loss, disease and weather damage by a waxy cuticle, which does not stop light entering the leaf.
• The upper part of the leaf is where the light falls, and it contains many cells called palisade cells. This has many chloroplasts, with lots of chlorophyll to trap as much light as possible. It is shaped like a tall box which helps pack them closely together.
• The lower part of the leaf is called spongy mesophyll. The air spaces between these cells allows gases such as carbon dioxide and oxygen to diffuse easily through the leaf.
• Here is the word equation for photosynthesis: carbon dioxide + water -> glucose+oxygen
• Photosynthesis is an exothermic reaction because energy is released when bonds form between molecules during the process.
• Plants and algae are producers and can only make their own food through photosynthesis
• Animals are consumers and they eat other animals to get energy and nutrients.