1. Photosynthesis Chapter 6 Biology

2. Energy and Life All living things need a source of energy to live All energy originates from the sun…. Ex.) What do you plan on having for lunch today?

3. Autotrophs and Heterotrophs “Auto”- make their own food and trap energy from the sun “Hetero”- get their energy by eating autotrophs or other heterotrophs

5. Energy and Life Energy come in many forms (motion, heat, etc.)

6. Energy is stored in chemical bonds as potential energy… When bonds between atoms are broken energy is released…because electrons shift from higher to lower energy levels

9. ATP Cells use ATP to store energy (Adenosine Tri-phosphate) Storing Energy? Add a phosphate group to ADP to make ATP Release Energy? Take ATP and remove a Phosphate group, and energy is released This energy is used for… active transport, protein synthesis, and muscle contraction

14. The Photosynthesis Equation Law of conservation of matter: Matter is neither created nor destroyed…rearranged Let’s balance this equation, why? Balancing Equations Practice…

15. XRAY: eggs2/ flour6/ bakingpowder2/ oil1 / water3

16. Go to the store Water Oil Baking aisle: The cake mix (egg1 / flour3 / bakingpowder1)

17. Now write the equation and figure out how much you need of each ingredient…

18. H and O makes water Write out the equation…and then balance it – Write out and balance the photosynthesis equation Come to some conclusion about it…

19. 8-2 An Overview of Photosynthesis Plants use energy from sunlight, water and carbon dioxide, to convert it to Carbs (sugars and starches) and oxygen.

21. The History Early scientists asked this question:  A tiny seedling grows into a large tree-  The amount of soil is the same  And water is the only thing that is added  Where does all the tree’s MASS come from then?

22. Van Helmont 1600’s Grew a seedling for 5 years and kept careful records …it gained 75kg Conclusion? All the mass came from water

23. Priestley 1700’s I know : Candles can’t burn without oxygen But…. If I place a candle under a jar with a mint sprig (plant), will the candle remain lit? Hypothesis: Conclusion:

25. Ingenhousz Improved upon Priestley’s findings Proves that this (photosynthesis) only works in the presence of light!

26. Photosynthesis requires.. ______ and ________ It also requires light and chlorophyll Chlorophyll absorbs light & is a pigment Light is energy… so when light is absorbed …so is energy

27. Light energy’s effect on chlorophyll molecule… When chlorophyll, located inside the chloroplasts of the leaf, traps energy from sunlight…. That energy is transferred to the electrons in the atoms of chlorophyll molecule, raising energy levels of the electrons and starting the process-

28. Review of Light concepts

29. White light contains all the colors of the rainbow Prism can break it apart so you can see it You see because light bounces off and object and to your eyes…in a straight line How do you see green? Red? White? Black? (is the color being absorbed or reflected)

30. 8-3 Light dependent vs Light independent Reactions photosynthesis includes the light- dependent reactions as well as the Calvin cycle (light independent).

31. The light-dependent reactions  Split water and produce oxygen gas  use trapped sunlight energy to convert ADP into ATP and NADP+ into NADPH  occur in the thylakoid membrane of the choloroplast

32. The light independent reactions use energy (ATP and NADPH) made during light-dependent reactions to produce high-energy sugars. (ATP and NADPH can only hold energy for a few minutes, it must be stored as a sugar long term) The Calvin cycle is also known as the light- independent reactions. LI reactions occur in the stroma (outside the thylakoid) American Scientist Melvin Calvin worked out the details of this cycle…

33. Factors that Affect Rate of Photosynthesis …. Shortage of water (slow or stop) Ideal temp for enzymes 0-35deg C  Too cold? ph can cease Intensity of Light (winter months)

34. Surviving in adverse conditions Desert plants adapted- waxy covering in order to retain water, curled leaves, etc

35. Surviving in adverse conditions Christmas trees (conifers) only occasionally carry out ph in the winter  They stay green but are not growing in the winter  The photosynthesis of most trees is completely shut down and they are living off of the stored sugars from the summer-

36. http://www.cnr.vt.edu/DENDRO/forestbiolo gy/photosynthesis.swf http://www.cnr.vt.edu/DENDRO/forestbiolo gy/photosynthesis.swf