1. IGCSE Coordinated Science Year 1 Energy Transformations in Living Organisms B4.2 & B6.1 Key Notes

2. Photosynthesis Photosynthesis is the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light. C C C C C C

3. Photosynthesis Uses the energy from sunlight to perform the reaction: 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Carbon Dioxide + Water Glucose (simple sugars) + Oxygen light energy chlorophyll light energy chlorophyll

4. Chloroplasts Chloroplasts are the location for photosynthesis

5. Chloroplasts Inside a chloroplast is the pigment chlorophyll. Chlorophyll absorbs certain wavelengths (colors) of light, trapping the energy from light.

6. Light Reflected Light Chloroplast Absorbed light Granum Transmitted light

7. The light energy is then converted into chemical energy and the production of simple carbohydrates. The carbohydrates are stored as starch.

8. Why is photosynthesis important to humans? Flow of Energy

9. More than sugar? So plants make glucose, but how do they get protein? What element is found in protein but not glucose? Plants make their own proteins but they must use nitrogen. Nitrogen can be absorbed from the soil. A good fertilizer adds nitrate to the soil.

10. Chlorophyll Synthesis? If plants want to make more chlorophyll, they need more magnesium.

11. What is wrong with this plant? Plants can have deficiency diseases too!

14. Natural fertilizers

15. Nitrogen-containing Fertilizers Chemical/Artificial fertilizers Contains elements: N-P-K

16. Fertilizer over-use Too much nitrogen can cause water pollution as it runs off in the water, causing “algae blooms” This is eutrophication.

17. PLANTS – TRANSPORT REVISION LAB REVISION

18. Review! Water transport in plants – Osmosis, transpiration via xylem – From roots to leaves Mineral ion transport in plants – Diffusion in through the roots, transported dissolved in water via xylem – From roots to leaves Organic Nutrient transport in plants – Translocation via phloem – From source to sink Plant Structure

19. The Pathway of Water Across a Root

20. Vascular Bundles Cross Section of a Root:

21. Cross Section of a Stem

22. Section of a Leaf

23. Dicot Leaf

25. What enters and exits through the stoma?

26. REVIEW A group of cells that perform the same function are called a…. TISSUE What are some tissues in a leaf?

27. Tissues – ex. palisade mesophyll

28. Leaf Structure What is each structure used for? (p. 66-67) Chloroplasts – – Photosynthesis (capture light energy to use when converting CO 2 into glucose) Stomata and mesophyll cells – – gas exchange via DIFFUSION Vascular bundles (xylem and phloem) – – transport and support

29. Experiment to show that light is required for photosynthesis

31. Variegated Leaves = green + white colored

33. Experiment to show that CO 2 is required for photosynthesis

34. Experiment to show that oxygen is a product of photosynthesis

35. 6.1 Respiration

36. What do you think our bodies use energy for? Our body uses energy for: – Muscle contraction – Protein synthesis (creation) – Cell division – Growth – Passing nerve impulses – Maintaining a constant body temperature

37. Energy Transformations Where does the body get it’s energy for these things? Where did that energy come from?

38. RESPIRATION Respiration is the chemical reactions that break down nutrient molecules in living cells to release energy.

39. Aerobic respiration is the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen. Energy

40. Aerobic Cellular Respiration Equation 6O 2 + C 6 H 12 O 6  6CO 2 + 6H 2 O + energy oxygen + glucose  carbon dioxide + water + energy

41. Let’s Watch it Work Aerobic respiration is done in both plant and animal cells. Let’s look at the graph of what is going on in the respiration chamber where there are some germinating (alive) beans. In your notes pages, record: – the changes you see in the graphs of O 2 & CO 2 concentrations – the conclusion you can draw from the data – What about the lab set-up makes this a fair test?

42. The Big Idea Compare and contrast photosynthesis & respiration.

43. Problem!! What happens when no oxygen is available for cells to use in respiration? How will our bodies get energy?

44. Yeast Anaerobic Respiration Lab Procedures: 1. Stretch out the balloon for a minute. 2. Put about 2 spoonful's of yeast + 2 spoonful's of sugar into the balloons using a funnel. 3. Turn the tap water on to WARM. It should not be too hot or too cold. 4. Add as much water as possible to the balloon without it overflowing. 5. Tie off the balloon while pushing out any remaining air. 6. Mix the contents of the balloon with your fingers until you feel no solid chunks left. 7. Return to your seat with the balloon, set it on your desk and wait….

45. Anaerobic Respiration Anaerobic respiration is the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen. We also call anaerobic respiration fermentation. Energy

46. In your muscles… During hard exercise our muscles do this type of anaerobic respiration: glucose  lactic acid + energy

47. Lactic Acid Can anyone describe what lactic acid buildup feels like in your muscles? What is oxygen debt? Read p. 119 & answer this question in your notes pages. How might the type of sport you play affect what type of respiration your cells perform?

48. In yeast… Yeast & other microorganisms do this type of anaerobic respiration: glucose  alcohol + carbon dioxide + energy

49. Anaerobic Respiration in Yeast The products of anaerobic respiration in yeast are valuable for brewing alcoholic drinks and bread making. Read p. 52 & 53 to find out more & answer these questions: – How is yeast involved in fermentation? – Why doesn’t bread taste like alcohol? – What makes bread soft and spongy? – What temperature do these (brewing & dough rising) take place at? Why?

50. Check out your balloons! What has happened to your balloons? Write a few sentences in your journal about how this has happened.