Plants and Photosynthesis 05/12/2018 Plants and Photosynthesis

Things needed for photosynthesis 05/12/2018 SUNLIGHT Gives the plant energy CHLOROPHYLL The green stuff where the chemical reactions happen WATER Travels up from the roots CARBON DIOXIDE Enters the leaf through small holes on the underneath

Photosynthesis equations 05/12/2018 Carbon dioxide + _____ glucose + _____ 6CO2 + 6H20 C6H12O6 + 6O2 Sunlight Chlorophyll The GLUCOSE produced by photosynthesis is used by the plant for _______ (through ____________). It is stored in the plant as ___________. Words – respiration, starch, water, oxygen, energy

Photosynthesis happens in the “palisade” cells in the leaf: 05/12/2018 Photosynthesis happens in the “palisade” cells in the leaf: Source: BBC Bitesize Palisade cells

Close up on a palisade cell: 05/12/2018 Cell wall Cell membrane Chloroplasts (containing chlorophyll) Large vacuole Nucleus Cytoplasm

Method for starch test: 05/12/2018 1) Cover up part of the leaf using black card What effect does this have on the plant? 2) Boil the leaf for a few minutes What does this do to the leaf? Soak the leaves in alcohol What effect does this have on the leaf? 4) Dip the leaves in water What effect does this have? 5) Drop some iodine onto the leaf What do you see? Draw and explain your results

NO LIGHT, NO PHOTOSYNTHESIS, NO STARCH! Results: 05/12/2018 The parts of the leaf which have been photosynthesising should have turned black. This shows that the part of the leaf which was covered up has not been photosynthesising, because it had no light. NO LIGHT, NO PHOTOSYNTHESIS, NO STARCH!

Root hair cells 05/12/2018 Plant roots are made of “root hair cells” which have two features that help them to take in water and nutrients: Root hair cells Large surface area Thin cell membrane

Using water Plants need water to do the following: Produce glucose 05/12/2018 Plants need water to do the following: Produce glucose Enable transport of minerals Form fruits Enable growth Keep the leaves cool

Photosynthesis and Respiration 05/12/2018 In earlier work we looked at respiration: Glucose + oxygen water + carbon dioxide Photosynthesis is the reverse of respiration: Water + carbon dioxide glucose + oxygen