Understanding Energy: From Photosynthesis to Cellular Respiration

1. Energy Worksheet • True or False – energy moves through a cycle (it is recycled through the environment)

2. Energy Worksheet • What do plants do with sunlight and what is “life’s universal food”? • What group of organisms directly consume plant sugar? • What group of organisms use the “leftover” biomass for energy? • Define metabolism. • Why can there never be more lions than gazelles? • Give three reasons we are indebted to plants. • What molecules are cycled in a living system?

3. Energy Worksheet • What two organelles does all life rely on for energy? • What processes take place within these organelles? • List the sequence of the real flow of energy through a system. • Sugar is important for two reasons. What are they?

4. Energy Worksheet

5. Energy and Life • Plants and some other types of organisms are able to use light energy from the sun to produce food. • Autotrophs – organisms such as plants which make their own food.

6. Energy and Life • Some organisms cannot use the sun to produce food. • Heterotrophs – obtain energy from the foods they consume.

7. Energy and Life • Energy comes in many forms such as light, heat, and electricity. • Energy can be stored as chemical compounds. • One of the principle chemical compounds that cells use to store and release energyis: • Adenosine triphosphate (ATP) • Basic energy source of all cells

8. Energy and Life • Storing energy • Adenosine diphosphate (ADP) • Releasing energy • Adenosine triphosphate (ATP)

9. Background of Photosynthesis • When a tiny seedling grows into a tall tree with a mass of several tons, where does the tree’s increase in mass come from? From the soil? From the water? From the air?

10. Photosynthesis • Van Helmont’s Experiment • Devised an experiment to find out if plants grew by taking material out of the soil. • Step 1 • Determined the mass of a pot of dry soil and a small willow seedling

11. Photosynthesis • Step 2 • Planted the willow seedling in the pot of soil

12. Photosynthesis • Step 3 • Water it regularly

13. Photosynthesis • Step 5 • At the end of five years Van Helmont weighed the tree and the soil

14. Photosynthesis • Results • Seedling gained about 75 kg (~169 pounds) • Mass of the soil was almost unchanged (weighed 2 ounces less) • Conclusions • Most of the gain of mass had come from the water because that is the only thing he added What could he conclude with what he knew?

15. Photosynthesis • Summarize Van Helmont’s experiment in approximately 3-5 sentences. Make sure you include his conclusions!

16. Photosynthesis • Priestley’s Experiment • Step 1 • Took a candle and placed a glass jar over it, and watched the flame gradually die out • Conclusion • Something in the air was necessary to keep the candle flame burning. OXYGEN

17. Photosynthesis • Step 2 • Priestley placed a live sprig of mint under the jar. • The candle could be lit and would remain lit for a while

18. Photosynthesis • Further testing: • Conclusion • Priestley discovered that a plant releases a substance that keeps a candle burning and a mouse living. This substance, oxygen, is released during photosynthesis.

19. Photosynthesis • Summarize Priestley’s experiment in 3-5 sentences. Be sure to include his conclusions!

20. Photosynthesis • Ingenhousz’sExperiment • Showed that the effect observed by Priestley occurred only when the plant was exposed to light • Conclusion: • Light is necessary for plants to produce oxygen • Summarize Ingenhousz’s experiment in 3-5 sentences. Be sure to include his conclusions!

21. Photosynthesis • Experiments performed by van Helmont, Priestley, and Ingenhousz led to work by other scientists who finally discovered that in the presence of light, plants transform carbon dioxide and water into carbohydrates, and they also release oxygen.

22. Photosynthesis You must know this equation! Reactants Products light 6 6 6 CO2 + H2O C6H12O6 + O2 chlorophyll Sugar (glucose) C: H: O: 1 2 3 1 12 8 6 12 18 C: H: O: 6 12 8 6 12 18

23. Write this down! Photosynthesis light 6 6 6 CO2 + H2O C6H12O6 + O2 chlorophyll Sugar (glucose) Cellular Respiration C6H12O6 + O2 6 CO2 + H2O + energy 6 6 Sugar (glucose)

24. Photosynthesis • Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high energy sugars and oxygen.

25. Photosynthesis • Pigments – substance that absorbs visible light • Most important for photosynthesis: • Chlorophyll a – primary pigment • Chlorophyll b – collects and passes energy to chlorophyll a • Accessory pigments – absorb other wavelengths of light • Carotene, xanthophyll, anthocyanin

29. Waterweed Simulation

31. Photosynthesis 1. Without using notes: write the reactants and products of photosynthesis! _________ + __________ ____________ + _________ Reactants Products

32. Waterweed Simulation 10 minutes to finish and drop!

33. Waterweed Simulation • The affect of light color on the rate of photosynthesis • RED • BLUE • GREEN • COLORLESS • What color showed the highest rate of photosynthesis? (look at your chlorophyll absorption worksheet) • Why?

34. Waterweed Simulation • The affect of light intensity on the rate of photosynthesis • 1-10 • What light intensity showed the highest rate of photosynthesis? • Why?

35. Waterweed Simulation • The affect of carbon dioxide level on the rate of photosynthesis • 1-10 • What carbon dioxide level showed the highest rate of photosynthesis? • Why?

36. Photosynthesis • Where does photosynthesis take place?

37. Photosynthesis Site of photosynthesis: CHLOROPLASTS • Chloroplasts contain: • Thylakoids • Granum • (stacks of thylakoids) • Stroma Light Dependent Reactions Light Independent Rxns / Calvin Cycle / Dark Reactions

38. Chloroplast Draw this in your notes!

39. Layers of a Leaf A. B. C. D. E. F. G. H. Cuticle Upper Epidermis Palisade layer Vein Spongy layer (air spaces) Lower Epidermis Stomata Guard Cells What layer of cells contain the most chloroplasts? Why? What is the purpose of the spongy layer, why are there air spaces in between the cells?

41. Stoma guard cells Stomata open when the internal pressure of the guard cells rises as a result of water absorption. Since the walls of the guard cells are relatively flexible at the side of the stoma, the guard cells expand vertically and the stoma subsequently opens.

42. Stomata Open stoma guard cells • Opening formed by two _______________. • Found on the _______________ of the leaf. • Allow _______ to enter the leaf. • Allow _______ and ______________ to exit. • Open by filling up with ___________. • Conserve water by closing __________. underside CO2 O2 watervapor water at night Closed stoma

43. Lilac Leaves • Take out your microscope and obtain a lilac leaf cross section. • Sketch and LABEL your leaf layers on MEDIUM POWER ONLY! Answer: • How does water reach the cells of the leaf? • Which layer of cells has the most chlorophyll? THINK ABOUT IT! • Where is the chlorophyll located inside the cells? • How does CO2 get into the leaf? • What regulates the stomata's?

44. Photosynthesis light 6 6 6 CO2 + C6H12O6 + H2O O2 chlorophyll Photosynthesis occurs in two stages

46. Photosynthesis • Light Dependent Reactions • Requires light • Occur in the grana (where chlorophyll is kept) • 4 Major events • H2O is split by energy from sunlight • Oxygen is released • H+ bonds with NADP  NADPH • ADP + P ATP

47. Photosynthesis • Light Independent Rxns / Dark Rxns / Calvin Cycle • DOES NOT require light • Occurs in the stroma • 2 Major events • CO2 joins with the H from NADPH to make glucose (C6H12O6) • ATP  ADP + P

50. Photosynthesis Play Extra Credit opportunity DUE MONDAY: TEN Points if you write a Photosynthesis play.