B. 影帶：光合作用所需條件：二氧化碳 光合作用所需條件：光強度 光合作用所需條件：水 光合作用所需條件：葉綠素 碳酸氫鹽/鈉指示劑的三種顏色：紫、紅、黃 顯微鏡下的葉綠體 http://www.hkbiology.net/experiments/transpire.htm#1

1. Why is the leaf first boiled in water? This kills the leaf and allows the ethanol / alcohol to pass into it.

2. Why is the leaf is then boiled in alcohol? To remove the chlorophyll / to decolourize for easy observation of the result.

3. Why is the leaf put in hot water after being boiled in alcohol? To soften the leaf

4. What colour change can be observed if starch is present? The leaf becomes blue-black.

Ch8: nutrition in plants photosynthesis

8.1: Photosynthetic Autotrophs 光合自養生物 Green plants are photosynthesis autotrophs which carry out photosynthesis (光合作用) to make complex organic food (glucose) from simple inorganic substances(H2O and CO2).

8.2: The process of photosynthesis 光合作用的過程 phos = light (Greek) Synthesis = putting together The process by which green plants use the chlorophyll (葉綠素) to change light energy to chemical energy for the production of sugars from H2O and CO2 Oxygen is released as a by-product (副產品) Sites of photosynthesis

8.3: the mechanism of photosynthesis 光合作用的機制 light reaction(光反應) + dark reaction(暗反應) Needs light does not need light Light reaction (光反應) 1. Chlorophyll absorbs light energy (colour) 2. The absorbed light energy is used to split分解 water molecules into hydrogen 氫 and oxygen氧 3. Oxygen diffuses out of cells into air. hydrogen is used in the dark reaction.

Dark reaction暗反應 occurs both in the presence of light or absence of light Hydrogen combines with CO2 , forming glucose and water.

Overall reaction of photosynthesis 光合反應的整體反應

A. Presence of lightaccumulation of starch 8.4: fate of carbohydrate products in plant 碳水化合物產品於植物體內的命運 A. Presence of lightaccumulation of starch Oxdized氧化 to release energy in respiration呼吸作用 to support growth etc. Transported as sucrose蔗糖 through the phloem靱皮部out of the leaf to storage organs or growing point生長點. Sugar will be changed to cellulose, fat, protein to support growth. Changed into insoluble starch 澱粉 for temporary storage . Flow chart hyperlinking

8.4: fate of carbohydrate products in plant 碳水化合物產品於植物體內的命運 A. absence of lightdestarching 脫澱粉過程 No photosynthesis takes place No sugar produced. The stored starch  sugar  oxidized 氧化 or transported away. This process is called destarching脫澱粉過程

8.5: Tests for photosynthesis products. A. Test for Starch in green leaf葉內澱粉試驗 (1) (2) (3) (4) Why is the leaf first boiled in water? Why is the leaf is then boiled in alcohol? Why is the leaf put in hot water after being boiled in alcohol? What colour change can be observed if starch is present?