1. Starter Activity: Draw a line down the middle of your show me board. On one side, you must write all the advantages of genetic engineering, and on the other, all the disadvantages – no notes!

2. Key Area 7 Photosynthesis

3. Learning Intention: We are learning the overall process of photosynthesis. Success Criteria: Be able to state what a carbohydrate is. Be able to write the word equation for Photosynthesis.

4. Watch and Listen Plants are Amazing!

5. Energy All our energy comes from the sun. Sun gives the energy to plants They make it in to food Plants pass its energy on to animals We eat the animals or plants (to get energy)

6. Plant Cell

7. Plants and Light Plants manufacture their own food in a process called PHOTOSYNTHESIS. When a plant carries out photosynthesis it combines simple substances to make carbohydrates like glucose and starch. Photosynthesis is carried out in the leaves of a plant. PHOTOSYNTHESIS (Light) (To build)

8. Photosynthesis Sunlight is extremely important as it provides the energy for plants to make their own food Cells in green plants make their own food in a process known as photosynthesis Photosynthesis is an enzyme-controlled process where light energy from the sun is trapped by chlorophyll and converted into chemical energy Chlorophyll is a green pigment (colour) found in disc-shaped structures called chloroplasts in green leaves

9. Carbohydrates The food that a plant makes is called glucose. Some of this is used immediately as an energy source and the rest is changed into starch for storage Starch is a large and insoluble molecule so it cannot leave the plant cell. Glucose and starch are carbohydrates made up of the following elements: carbon (C) Hydrogen (H) Oxygen (O)

10. Watch and Listen Photosynthesis Video Clip While watching this clip, think about how green plants affect the composition of gases in the atmosphere.

11. Photosynthesis Equation Carbon Dioxide +WaterGlucose+Oxygen 6CO 2 6H 2 OC 6 H 12 O 6 6O 2 Raw Materials Products chlorophyll Light energy The process of photosynthesis converts light energy into chemical energy.

13. Photosynthesis Learning Intention: We are learning the overall process of photosynthesis Success Criteria: Be able to state what a carbohydrate is Be able to write the word equation for photosynthesis

14. Starter Activity: On a show me board, using no notes, write out the photosynthesis word equation. Make sure you label the raw materials and products. Question - How do green plants affect the composition of gases in the atmosphere?

15. Photosynthesis Learning Intention: We are learning how to test a leaf for the presence of starch Success Criteria: Be able to take part in an investigation to prove that a leaf is photosynthesising Be able to describe the experiment carried out Be able to name the solution used to test for starch

17. Investigating Conditions Needed for Photosynthesis Before we can carry out investigations to find out the conditions required for photosynthesis, we need to know the process for proving that a leaf has photosynthesised What do you think we will test a leaf for?

18. Testing a leaf for starch Important Points: 1) We boil the leaf to remove the waxy coating so our stain can get inside the leaf 2) We place the leaf in ethanol to remove the green colour so we can see the colour change.

19. Method 1)Place the leaf in a beaker of water. 2)Sit the beaker on a tripod stand and use a Bunsen Burner to boil the water. 3)TURN OFF THE BUNSEN BURNER. 4)Using tweezers, remove the leaf. 5)Place the leaf in a boiling tube with ethanol. 6)Place the boiling tube into the beaker of water. 7)Once the ethanol has turned green, remove the leaf using tweezers and test for the presence of starch, using Iodine solution.

20. Set up your experiment 100 ml of water in 250 ml beaker

21. Proving that Light is Required Discuss with your partner how you think you can prove that light is required for photosynthesis to take place Your teacher will listen to all of your ideas You will then carry out an experiment to prove your hypothesis

22. Photosynthesis Learning Intention: We are learning how to test a leaf for the presence of starch Success Criteria: Be able to take part in an investigation to prove that a leaf is photosynthesising Be able to describe the experiment carried out Be able to name the solution used to test for starch

23. Starter Activity: What leaf (Q or R) would test positive for starch? Why?

24. Photosynthesis Learning Intention: We are learning to use skills we have already learned to carry out an investigation Success Criteria: Be able to carry out an investigation to prove that chlorophyll is required for photosynthesis

25. Light energy from the sun is used by green plants to make their own food. Light energy is trapped by green pigment called chlorophyll Chlorophyll found in disc- shaped structures called chloroplasts Chlorophyll (green pigment )

26. Conditions Required for Photosynthesis You will now carry out the test for starch on a variegated leaf Write down your hypothesis.

27. Set up your experiment 100 ml of water in 250 ml beaker

28. Task Write up your experiment including your aim, variables, method and results. You must include a labelled diagram. You must include the reasons for boiling the leaf and for resting it in alcohol.

29. Photosynthesis Learning Intention: We are learning to use skills we have already learned to carry out an investigation Success Criteria: Be able to carry out an investigation to prove that chlorophyll is required for photosynthesis

30. Starter Activity: Describe an experiment which shows that carbon dioxide is required for photosynthesis. You will need to use your knowledge from the “testing a leaf” experiment.

31. Photosynthesis Learning Intention: We are learning stage 1 of photosynthesis Success Criteria: Be able to name, describe and explain stage 1 of photosynthesis Be able to state the conditions required for stage 1

32. Photosynthesis Song

33. Photosynthesis Carbon Dioxide +WaterGlucose+Oxygen CO 2 H2OH2OC 6 H 12 O 6 O2O2 Light energy Raw MaterialsProducts

34. Photosynthesis (stage 1) Photosynthesis happens in 2 stages. Stage 1 is the Light Reaction. It is sometimes called Photolysis.

35. Light energy Light energy trapped by chlorophyll in chloroplasts Water from roots Excess Oxygen diffuses from the cell water is split into oxygen and hydrogen Hydrogen attaches to hydrogen acceptor molecules. Light energy is converted to chemical energy : ADP + Pi  ATP.

36. Light Reaction Stage 1 is sometimes called photolysis. Occurs in the chloroplasts. Splitting of water into oxygen and hydrogen. Oxygen is produced and excess oxygen diffuses into the air. Light energy is converted to chemical energy in the form of ATP (ADP + Pi  ATP). Hydrogen attaches to the hydrogen acceptor molecules. ATP and hydrogen are used in stage 2.

37. Task In groups, pupils should play a part in a short production to show their class what happens during the light reaction. Each person in the group must take part. You may use Show Me Boards or paper to help demonstrate the light reaction.

38. Photosynthesis Learning Intention: We are learning stage 1 of photosynthesis Success Criteria: Be able to name, describe and explain stage 1 of photosynthesis Be able to state the conditions required for stage 1

39. Starter Activity: Answer the following questions in your class work jotter: 1)Name the two raw materials of photosynthesis 2)Name stage 1 3)Why is it sometimes referred to as the light- dependant stage? 4)What is the energy change that takes place? 5)Name two products made in stage 1 that are required for stage 2

40. Photosynthesis Learning Intention: We are learning stage 2 of photosynthesis Success Criteria: Be able to name, describe and explain stage 2 of photosynthesis Be able to state the conditions required for stage 2

41. Photosynthesis (stage 2) Photosynthesis happens in 2 stages. Stage 2 is called Carbon Fixation.

42. Hydrogen from stage 1 ATP from stage 1 Carbon dioxide (from air) Glucose formed

43. Carbon Fixation Stage 2 – sometimes referred to as temperature- dependent stage as it’s controlled by series of enzymes. ATP (from stage 1) provides energy for this process. Hydrogen from stage 1 combines with CO 2 from the air to form glucose. The chemical energy in glucose is available for respiration or can be converted into other substances.

44. Task Take a full page of your notebook and draw the two stages of photosynthesis linked together.

45. Task In groups, pupils should play a part in a short production to show their class what happens during the whole process of photosynthesis. Each person in the group must take part. You may use Show Me Boards or paper to help demonstrate the process.

46. Consolidation Task read Collect a National 5 text book and read pages 76 to 83. You must complete: Activity 7.1 working individually in your notebook, answering in FULL sentences. You should complete: Activity 7.2 working individually in your notebook, answering in FULL sentences. You could complete: Activity 7.3 working in pairs on A3 paper.

47. Photosynthesis Learning Intention: We are learning stage 2 of photosynthesis. Success Criteria: Be able to name, describe and explain stage 2 of photosynthesis. Be able to state the conditions required for stage 2.

48. Starter Activity: Answer on a show me board: Why is the glucose made in photosynthesis converted to starch?

49. Photosynthesis Learning Intention: We are learning the different uses of glucose in a plant cell. Success Criteria: Be able to name the two carbohydrates that glucose can be converted to. Be able to explain why each of the carbohydrates is suited to its function.

50. So... The final product is glucose. We already know that glucose can be converted to starch because starch is storage carbohydrate. Glucose can also be converted into cellulose, a structural carbohydrate – used to build cell walls.

51. Photosynthesis So what happens to the sugar made in the leaves? It can be used in a number of ways Glucose Used as building Material (e.g. cellulose in cell walls) Used immediately for energy Stored as starch and converted back when Sugar is needed by Plant

52. Starch A single starch molecule can be made up from around 200-800 glucose molecules. The glucose molecules are joined in coiled chains.

53. Comparing Starch and Cellulose Starch molecules and cellulose molecules are both large molecules. They are both built up from glucose. This happens as a result of glucose molecules being linked together in different ways. They have different structural arrangements and properties.

54. Starch continued… Starch molecules are large and insoluble in water. They act as concentrated energy stores. Starch is made of long coiled chains of glucose and stored in the form of a starch grain. Starch is called a storage carbohydrate.

55. Cellulose A single cellulose molecule is likely to be made up from around 1000 – 1500 glucose molecules. Cellulose is made up of chains of linear glucose molecules.

56. Cellulose continued….. Cellulose molecules are also insoluble in water and are not easily broken down. This makes them particularly suitable for use as a structural component of cell walls in plants. Cellulose is therefore known as a structural carbohydrate.

57. Photosynthesis Learning Intention: We are learning the different uses of glucose in a plant cell. Success Criteria: Be able to name the two carbohydrates that glucose can be converted to. Be able to explain why each of the carbohydrates is suited to its function.

58. Starter Activity: On a show me board, using no notes, write down the three elements found in a carbohydrate.

59. Photosynthesis Learning Intention: We are learning to investigate the limiting factors of Photosynthesis. Success Criteria: Be able to name the three limiting factors of photosynthesis. Be able to carry out an investigation to measure the rate of photosynthesis.

60. Photosynthesis Photosynthesis CANNOT work without: Carbon dioxide The correct temperature Sunlight If any of the above are in short supply they are said to be “Limiting Factors”.

61. Limiting Factors The three limiting factors of photosynthesis are: temperature, carbon dioxide concentration and light intensity. By increasing the limiting factors, you can increase the rate of photosynthesis and therefore, rate of plant growth.

62. Success Criteria Your news/weather report must: Be between 1 and 3 minutes long Have a contribution from every group member Contain the process of photosynthesis Your news/weather report should: Be factually correct Be spoken in a varied tone Your news/weather report could: Have interesting facts for your audience Be entertaining, as well as informative Garden Weather/News Report

63. Limiting Factors Discuss with your partner what would happen to the rate of photosynthesis if you increased the temperature to above its optimum. Why do very high temperatures cause the rate of photosynthesis to drop to zero? Think back to the enzymes topic.

64. Measuring the rate of photosynthesis This can be measured by: -rate of CO 2 uptake -rate of O 2 production -rate of build up of starch/carbohydrate The easiest of these to measure is O 2 production in plants which live in water.

65. Pondweed Cabomba Elodea These plants produce tiny oxygen bubbles which are released into the water. This is good for the fish in a fish tank! What do the plants get from the fish in return?

66. Cabomba / Elodea bubbler By counting the bubbles of oxygen released per unit of time, we can measure the rate of photosynthesis

67. Elodea Bubbler X Y What could be limiting the rate of photosynthesis at point X? What could be limiting the rate of photosynthesis at point Y? Z 0.5 conc of CO2 25 0 C 0.5 conc of CO2 15 0 C What could be limiting the rate of photosynthesis at point Z?

68. Elodea Bubbler What happens as light intensity increases? The rate of photosynthesis increases then levels off. Why does it level off? Something else must be in short supply.

69. Elodea This animation helps demonstrate how limiting factors affect the rate of photosynthesis. http://www.kscience.co.uk/animation s/photolab.htm

70. Measuring rate of photosynthesis with Elodea (pondweed) elodea Solution of sodium carbonate (a source of CO 2 ) Thermometer lamp funnel Upside down test tube (to collect oxygen gas) How could the light intensity be altered? How could the temperature be altered (and kept constant)? How could the CO 2 concentration be altered? How can the rate of photosynthesis be measured?

71. Light intensity as a limiting factor Light intensity A B At A, low light intensity is limiting the rate of photosynthesis. At B, light intensity is high, so another factor must be in short supply (carbon dioxide concentration or temperature).

72. Carbon dioxide concentration as a limiting factor Carbon dioxide concentration A B At A, low carbon dioxide concentration is limiting the rate of photosynthesis. At B, carbon dioxide concentration is high, so another factor must be in short supply (light intensity or temperature).

73. Temperature as a limiting factor Temperature (°C) A B At A, low temperature is limiting the rate of photosynthesis. At B, temperature is high, so another factor must be in short supply (carbon dioxide concentration or light intensity). But what happens after 40°C? 400 20

74. Temperature as a limiting factor At very high temperatures, the rate of photosynthesis drops down to zero. Why do you think this happens? (Think back to the enzymes topic.)

75. Limiting factor graphs The temperature graph is different due to the enzymes that control photosynthesis being denatured at high temperatures.

76. Limiting Factors Light Intensity At this point, light intensity is the limiting factor At this point, something other than light intensity is the limiting factor. It must be either CO 2 concentration or temperature. As a general rule, whatever is on the x-axis is the limiting factor on the slope of the graph.

77. What’s the limiting factor? Your teacher will add a label to the x axis. You can then try to complete the sentences. A B At A, low ________________ is the limiting factor. At B, ___________ or ______________ is the limiting factor.

78. Photosynthesis Learning Intention: We are learning to investigate the limiting factors of photosynthesis Success Criteria: Be able to name the three limiting factors of photosynthesis Be able to carry out an investigation to measure the rate of photosynthesis