Photosynthesis

1. Photosynthesis Chapter 8

2. Vocabulary—Breaking Down the Definitions • Photosynthesis • Pigment • Chlorophyll • Thylakoid • Stroma • NADP+ • Light Dependent Reactions • ATP Synthase • Calvin Cycle

3. Photosynthesis—What Do We Already Know?

4. Photosynthesis Brain Pop

5. Chemical Equation—Quiz on this Next Meeting! 6 6

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

7. Light and Pigments • In addition to water and carbon dioxide, photosynthesis also requires LIGHT and CHLOROPHYLL. • CHLOROPHYLL= a molecule within a chloroplast • Chlorophyll is a pigment that absorbs light

8. IVF to Analyze the Graph!

9. 2 Stages of Photosynthesis

10. Inside a Chloroplast • Photosynthesis takes place inside a chloroplast • The chloroplast contains saclike membranes called THYLAKOIDS • THYLAKOIDS are arranged in stacks called GRANA • The Chlorophyll is inside the thylakoids • The STROMA is the region outside of the thylakoids

12. Light Reactions • The first stage of photosynthesis is the LIGHT REACTIONS. • Light is absorbed by the chloroplasts • Light Energy is converted to Chemical Energy (stored in ATP and NADPH)

13. Light Reactions Continued • Oxygen is given off during this reaction. --Leaf Demo-- • Chlorophyll in the chloroplast contains pigments (compounds that absorb light) that absorb a lot of blue and red light but reflect green light (giving plants their green color.

14. Light Reactions Continued • An oxidation reaction takes place, losing electrons and the primary electron acceptor takes on the lost electrons in a reduction reaction. • The primary electron acceptor donates the electrons to a series of molecules in the thylakoid membrane of the chloroplast.

15. Oxygen as Byproduct Demo

16. Label the diagram

17. Dark Reactions/Calvin Cycle • In the second set of reactions in photosynthesis plants use the energy that was stored in ATP and NADPH during the light reactions to produce sugars. • Most common way this is done is called the CALVIN CYCLE. • Calvin Cycle Song!

18. 4 Steps of the Calvin Cycle Step 1 • 3 CO2 molecules diffuse into the stroma and combine with a 5-Carbon molecule, RuBP. This molecule is very unstable and it quickly splits into 2 3-Carbon molecules called 3-PGA. • Each 3-PGA is converted into another 3 Carbon molecule, G3P after receiving a phosphate group from ATP and a proton from NADPH. Step 2

19. 4 Steps of the Calvin Cycle Step 3 • One of the G3P molecules leave the Calvin Cycle to make carbohydrates which are stored for later use. • The remaining 3GP molecules are converted back into RuBP by adding phosphate groups from ATP and then the Calvin Cycle begins again. Step 4

20. Step 1—3 CO2 molecules combine to form RuBP (6 carbon molecule) which splits into 3 PGA Step 4– The rest of the G3P is converted back into RuBP/Rubisco Calvin Cycle Step 3– One molecule of G3P leaves the cycle to make sugars Step 2—Each molecule of 3 PGA is converted to G3P

21. Factors Affecting Photosynthesis • Water, Temperature, Intensity of Light all affect the rate of photosynthesis

22. Thinking Visually • Complete the flowchart on page 216 of your book.

23. Investigation Photosynthesis