2. Photosynthesis Chapter 8 Cellular Energy Page 216

3. Objectives SWBAT: describe the role of ATP in metabolism SWBAT: summarize how energy is captured from the sunlight and transformed into usable products. SWBAT: identify 3 environmental factors that affect the rate of photosynthesis.

4. Your thoughts What do you think of when you hear the word energy?

5. Section 1 – How organisms obtain energy Energy is …

6. Section 1 – How organisms obtain energy The ultimate source of energy for all living this is the … SUN This energy can be captured to make organic compounds

7. Autotroph: an organism that uses energy from sunlight to make food Chemoautotroph: uses inorganic substances as a source of energy Photoautotroph: convert energy from the sun

8. Heterotroph: – An organism that must get energy from other organisms by consuming them – Herbivore – Omnivore – Carnivore – Detritivore

9. : Metabolism: Sum of all chemical reactions in an organism Used to build molecules for energy Breaks down molecules in which energy is stored

10. Pathways CATABOLIC Energy is released Breaks down large molecules to smaller Cellular Respiration ANABOLIC Uses energy from catabolic Builds larger molecules Photosynthesis

11. Anabolic pathway in which light energy from sun is converted to chemical energy for cell use Reactants= CO2, water, light Products = O2, glucose

12. Cellular Respiration Catabolic pathway where organic molecules are broken down to release energy for cell use Reactants = glucose, O2 Products= CO2, water, energy

13. Adenosine Tri-phosphate When cells break down food molecules, some of the energy in the molecule is released as heat Much of the remaining energy is store in molecules of ATP

14. Breaking down food for energy ATP  ADP + P + energy When the phosphate bond breaks – a release of energy is given to the body This reaction will power most of the chemical reactions in an organism + P ATPADP

15. Essential Questions Differentiate between an autotroph and heterotroph Differentiate between catabolic and anabolic pathways How does ATP work in a cell? Vocabulary: energy, metabolism, photosynthesis, cellular respiration, ATP

16. Section 2 - Photosynthesis The process by which light energy is converted to chemical energy

17. THE EQUATION of Photosynthesis 6CO 2 + 6H 2 O yields C 6 H 12 O 6 + 6O 2 Light energy

18. SUGAR

19. Phases of Photosynthesis Light Dependent Reaction – Light is absorbed and converted to chemical energy (ATP/NADPH) – Occurs in the thylakoid Light Independent Reaction – ATP/NADPH used to make glucose – Occurs in the stroma

21. A chloroplast In which stage does each occur?

22. LIGHT Is a form of radiation (energy) that travels in waves through space Visible light spectrum: – the light we see – ROY G BIV

24. PIGMENTS A light absorbing colored molecule. Some light wavelengths will be absorbed and others will be reflected Chlorophyll the primary pigment Types a, b Absorbed light: blue, violet, red light Reflected light: green light SEE= Green

25. SECONDARY PIGMENT – Type - carotenoids – Absorbed light= green, blue, purple – Reflected light= Red, Orange, Yellow – Give the body Vitamin A and beta carotene

26. Where does is all begin? Sun Chloroplast

27. Plants that have alternative cycles C4 Plants – CO2 fixation is different than normal – This helps to minimize water loss due to its harsh environment – Example: sugarcane, corn

28. Plants that have alternative cycles CAM PLANTS – CO2 enters only at nite – CO2 fixation occurs only at nite – CO2 released during the day – This all minimizes water loss – Example: desert plants (cacti), pineapple

29. Stage #1 Show overhead LIGHT DEPENDENT REACTIONS Occurs in the THYLAKOID Needs light

30. Light reaction steps The chlorophyll in the thylakoid receives energy from the sun Light energy is absorbed by the excited e- Excited e- cause even more to become excited This excitement and jumping causes water to be broken down Water is spilt into O, H, H (AKA excited e-) O2 is given off as a gas

31. Part 2 of Phase 1 = Electron Transport Chain The excited e- accumulate in the thylakoid membrane A protein embedded in the thylakoid membrane acts like a pump This pump will bring the excited e- in and out of the thylakoid membrane As a result, ATP and NADPH are created These are energy carrier molecules that help power the Light Independent reactions

33. Summing up Light Reactions Chlorophyll absorbs light energy Water is split H + accumulates in the thylakoid membrane Oxygen is released H + builds up a gradient that provides energy to create ATP and NADPH

34. Light Independent reactions Does not need to be in the light to occur Occurs in the stroma of the chloroplast Uses ATP/NADPH to create glucose AKA – Calvin cycle – Carbon dioxide fixation

35. Calvin Cycle ATP and NADPH provide the cells with large amounts of energy and help to power the Calvin Cycle This stage uses CO2 to help produce glucose 1 CO2 molecule is added to a 5-carbon compound This makes a 6 carbon compound Then it splits into 2 three-carbon compounds One of these 3 carbon compounds is used to create glucose The other goes back in the cycle

36. Check this out http://faculty.nl.edu/jste/calvin_cycle.htm Check this site out….. It puts all of the Calvin Cycle together in an animation

38. The End Products Oxygen Glucose Sugar

39. Factors that affect Photosynthesis Light Intensity – As light energy increases the rate of photosynthesis also increases until all pigments are used Photosynthesis Amount of light

40. Factors that affect Photosynthesis Carbon Dioxide – Once a certain amount of CO2 is present, photosynthesis cannot proceed any further Photosynthesis Amount of CO 2

41. Factors that affect Photosynthesis Temperature – Plants operate at a certain temperature range (20-30C) – Thus increasing temperature will decrease the rate of photosynthesis – Decreasing temperature will decrease the rate photosynthesis Amount of heat Photosynthesis

42. Questions to ponder… Why do plants grown in the sun have smaller leaves than those grown in the shade? What is the main source of the excited electrons? What is the source of some of the replacement electrons? What type of membrane protein is involved in photosynthesis? What is the role in photosynthesis of the following: light, water, chlorophyll, pigment, ATP, NADPH, and CO 2 ? What stage of photosynthesis would each of the limiting factors effect?

43. AutotrophHeterotroph PlantsAnimals Produce their own food Depend on others for food Needs carbon dioxide & water Needs oxygen Produces oxygen & sugar Produces water & CO 2 Self - feeder Other - feeder Go thru photosynthesis and metabolism Go thru metabolism

44. Light Reactions Calvin Cycle Occurs in the thylakoidOccurs in the stroma Needs lightDoes not need light but does need CO 2 Absorbs light and converts it into chemical energy Uses chemical energy to turn it into food Produces O 2 and ATPProduces sugar