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Photosynthesis . Photosynthesis: uses the energy of sunlight to convert water and carbon dioxide into high energy carbohydrates6CO2 6H2O ---light? C6H2O6 6O2Carbon dioxide water --- light? sugars oxygen . Photosynthesis Equation. 6CO2 6H2O ---light? C6H2O6 6O2Reactants: carbon di
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1. Photosynthesis Chapter 8-2 and 8-3
2. Photosynthesis Photosynthesis: uses the energy of sunlight to convert water and carbon dioxide into high energy carbohydrates
6CO2 + 6H2O ---light? C6H2O6 + 6O2
Carbon dioxide + water --- light? sugars + oxygen
3. Photosynthesis Equation 6CO2 + 6H2O ---light? C6H2O6 + 6O2
Reactants: carbon dioxide
water
Products: carbohydrates
oxygen
4. Who does photosynthesis? Plants and other organisms that contain the pigment, chlorophyll
Chlorophyll is stored in the chloroplasts of a plant cell
5. Where does photosynthesis happen? Photosynthesis occurs within the chloroplasts
6. Chloroplasts Thylakoids- photosynthetic membranes
Granum- stack of thylakoids
Stroma- space outside the thylakoids
Photosystems- clusters of pigment & protein that absorb light energy (I & II)
7. Two Parts of Photosynthesis Light dependent reactions- take place within the thylakoid membranes
Light independent reactions (Calvin Cycle)- takes place within the stroma
8. Light Dependent Reactions Figure 8-10 on page 211
Sunlight is absorbed by Photosystem II
The sunlight breaks down water molecules stored within Photosystem II
The water is broken and its electrons gain energy
These excited electrons leave the photosystem and are passed through an electron transport chain
9. Light Dependent Reactions As the electrons move, they provide energy to move H+ ions from the stroma across the thylakoid membrane into the thylakoid
When the electrons reach Photosystem I, they are reenergized by sunlight
10. Light Dependent Reactions The reenergized electrons are picked up by NADP and are used to create NADPH
At the same time, electrons inside the thylakoid create a concentration gradient of H+ ions
This gradient is used to power an enzyme called ATP synthase, which synthesizes ATP
11. Light Dependent Reactions Reactants: water
sunlight
NADP
ADP
Products: Oxygen
NADPH
ATP
12. Electron Transport
13. ATP Synthase
14. Light Independent Reactions: The Calvin Cycle The Calvin Cycle uses the NADPH and ATP produced in the light dependent reactions to create high energy sugars
Figure 8-11 on page 212
15. The Calvin Cycle Carbon dioxide molecules from the atmosphere enter the stroma
The carbon dioxide joins with other carbon molecules to form 3-carbon molecules called PGA
The PGA molecules use energy from ATP and NADPH to convert into PGAL
16. The Calvin Cycle Some of the PGAL leaves the cycle and is used in other parts of the plant cell
But the majority of PGAL molecules are converted back into PGA and continue in the cycle
After six rounds of the Calvin Cycle, one molecule of glucose is produced
17. The Calvin Cycle Reactants: Carbon Dioxide
NADPH
ATP
Products: Glucose
18. The Calvin Cycle
19. Photosynthesis