SASS Bio Nutrition in Plants Notes

6093 Biology Chapter 7 Nutrition in Plants CT_2020 1 ST ANDREW’S SECONDARY SCHOOL Secondary 3 Biology (6093) Chapter 7: Nutrition in Plants Name: ______________________ ( ) Class: _________ Date: _____________ 7.1 Photosynthesis • Plants are able to synthesise their own food by the process of photosynthesis. • Photosynthesis is a process in which light energy is absorbed by chlorophyll and converted to chemical energy. 5. Nutrition in Plants Content • Leaf Structure • Photosynthesis Learning Outcomes Candidates should be able to: a) identify and label the cellular and tissue structure of a dicotyledonous leaf, as seen in transverse section using the light microscope and describe the significance of these features in terms of their functions, such as the • distribution of chloroplasts in photosynthesis • stomata and mesophyll cells in gaseous exchange • vascular bundles in transport b) state the equation, in words and symbols, for photosynthesis 
 c) describe the intake of carbon dioxide and water by plants 
 d) state that chlorophyll traps light energy and converts it into chemical energy for the formation of carbohydrates and their subsequent uses 
 e) investigate and discuss the effects of varying light intensity, carbon dioxide concentration and temperature on the rate of photosynthesis (e.g. in submerged aquatic plant) f) discuss light intensity, carbon dioxide concentration and temperature as limiting factors on the rate of photosynthesis 
 Use the knowledge gained in this section in new situations or to solve related problems.

6093 Biology Chapter 7 Nutrition in Plants CT_2020 2 • Inorganic molecules of carbon dioxide and water are used for the synthesis of an organic molecule of glucose. • Oxygen is released as a by-product. Where does photosynthesis occur? The light-dependent (light) and light-independent (dark) stages in photosynthesis. 1. Enzymes catalyse a series of reactions involved in the light and dark stages of photosynthesis. Green leaves Leaf’s _________ layer Cytoplasm of the mesophyll cells In an organelle called the chloroplast, which contains the green pigment chlorophyll

6093 Biology Chapter 7 Nutrition in Plants CT_2020 3 2. During the light stage of photosynthesis, the following processes occur: a. Trapping of light energy by chlorophyll b. Conversion of light energy to chemical energy c. Splitting/photolysis of water into hydrogen atoms and oxygen gas. 3. During the dark stage of photosynthesis, the chemical energy and hydrogen atoms produced from the light stage are used to reduce carbon dioxide to form glucose. The overall word equation of photosynthesis: carbon dioxide + water → glucose + oxygen [do not state energy as a product!] The overall chemical equation of photosynthesis: 6 CO2 + 12 H2O → C6H12O6 + 6O2 + 6 H2O The simplified chemical equation for photosynthesis: 6 CO2 + 6 H2O → C6H12O6 + 6O2 Limiti