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7 Cards in this Set
- Front
- Back
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Purpose of destarching |
- Ensures starch is absent in the leaves before the experiment - So that all starch present after the experiment must have been formed during it |
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Purpose of placing leaf in boiling water (Experiment: test for starch in leaf) |
- To denature enzymes in the leaf to stop photosynthesis - Make cell membranes fully permeable (why?) |
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Purpose of placing boiled leaf in alcohol (Experiment: test for starch in leaf) |
- Fully extracts chlorophyll from leaf - Leaf is decolourised (turns white) and contents of tube turn green |
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Substances which absorb carbon dioxide (4) |
1. Soda lime 2. Potassium hydroxide solution 3. Sodium hydroxide 4. Calcium hydroxide |
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Purpose of polythene bag |
- Soil contains microorganisms that respire and give out carbon dioxide which interferes with experiment - Polythene bag contains the carbon dioxide |
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Substances that produce carbon dioxide (3) |
1. Sodium hydrogencarbonate 2. Baking soda 3. Bicarbonate powder |
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Define photosynthesis |
The process in which - light energy absorbed by chlorophyll - is transformed into chemical energy. - This C.E. is used to synthesise carbohydrates from water and CO2, - which are the raw materials for photosynthesis. - Oxygen is released as a by-product. |
