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9 Cards in this Set
- Front
- Back
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Photosynthesis
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-Solar energy is converted into chemical energy.
-Convert CO2 and water into glucose and O2. -It takes place in a chloroplast Two reactions: 1. Light reactions 2. Dark reactions |
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Chloroplast
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-Contains the chlorophyl pigment, it traps the light pigment.
-Contains a network of membranes: thylakoid membranes -Chlorophyll is inside of the thylakoid. -Thylakoid sacs are stacked into columns called grana. -Fluid of the chloroplast: stroma |
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Chlorophyll
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Two types: chlorophyll a and b
-They absorb photons of light and boost the electrons to an excited state. |
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Photosystem I
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Chlorophyll a is known as P700
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Photosystem II
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Chlorophyll a is known as P680
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Light Reactions
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1. Absorption of a photon of light by chlorophyll a P700.
2. Excites electrons to higher energy level. 3. Can flow along cyclic electron flow or noncyclic electron flow. |
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Cyclic Electron Flow
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-Excited electrons of P700 move down a chain of electron carriers, and then returns them to P700.
-This produces ATP |
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Noncyclic Electron Flow
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-Key pathway of light reactions
1. Instead of electrons returning to P700, the electrons are transfered to NADP+. 2. It accepts them and turns into NADPH. 3. P700 has holes in it, making it a good oxidizing agent. 4. Light strikes P680 in photosystem II, and electrons are excited. 5. Electrons travel down same electron carrier to P700, and fill "holes". 6. This produces ATP. 7. Now, P680 has "holes" |
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Dark Reactions
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-Use ATP and NADPH produced by light reactions to reduce CO2.
-They only occur during day when light reactions are occurring. -CO2 is source of carbon for carbohydrate production in Calvin Cycle. |
