Science

STUDENT’S NAME:____________________________________ DATE:____________ FINAL SCORE:_____________

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2.1 BEFORE THE EXPERIENCE.

1. TOPIC:Photosynthesis and starch production

2. THROUGHLINE: Is starch produced in the absence of light and carbon dioxide?

3. UNDERSTANDING GOALS.a. The student understands the main structures offlowering plants and their role in plant life processes. b.The student explains the processes of transport, photosynthesis and reproduction in flowering plants. |

4. HYPOTHESIS.




5.INTRODUCTIONPhotosynthesis is the process by which light energy is obtained by chlorophyll and used to convert carbon dioxide and water into the products of glucose and oxygen. Most photosynthesis takesplaces in the green parts of plants, in particular the leaves. Photosynthesis involves 2 stages - the Light-dependent Stage and the Light-independent stage. In the light-depedent stage, water is broken upby sunlight into Hydrogen and oxygen. Hydrogen enters the second stage (light-independent), oxygen is gaseous by-product.In the light - independent stage, a carbohydrate, glucose is first formed fromcarbon dioxide and water. Glucose may be immediately used, transported through the phloem in the form of fructose or sucrose or stored as starch granules.To check if starch is produced, iodinesolution will be used to check if starch is present in the leaves. |

6. MATERIALS. Green leafs, forceps, beaker, tray, aluminum foil, bunsen burner, water, ethanol. iodine solution. |

7.PROCEDURE. 1. Remove a green leaf fom a plant that has been exposed to sunlight for a few hours 2. Half-fill a 250cm3 beaker with water. Heat the water until it boils. Keep the water at boiling point.3. Use the forceps to place the leaf in the boiling water. Boil for 2 minutes. 4. Turn off the Bunsen Burner. (If you are using a heat source without a naked flame - electric water bath or hot...