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55 Cards in this Set
- Front
- Back
Where does photosynthesis occur? |
In chloroplasts |
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How many chloroplasts are typically in a cell? |
40 to 50 chloroplasts |
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What is a thylakoid? |
Vesicle like structure in chloroplasts |
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Lumen |
Interior of any sac-like structure |
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Pigments |
Molecules that absorb wavelengths and protect the cells |
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What color does chlorophyl A and B absorb |
Red wavelength/ blue wavelength |
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What colors do cartenoids absorb? |
Colors not absorbed by chlorophyll such as green and yellow light. |
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What are the 2 classes of cartenoids? |
Carotenes and xanthophylls |
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How do cartenoids protect chlorophyll molecules? |
Cartenoids "quench" free radicals by accepting or stabalizing unpaired electrons. |
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What are Flavenoids? |
Flavenoids are accesory pigments that absorb UV light. |
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Whats the base structure of Chlorophyl A and B? |
A long tail made out of isoprene subunits and a "head" consisting of a large ring structure with Mg in the middle. |
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Whats the purpose of the "tail" in Chlorophyl A and B? |
Keeps the molecule embeded in the thylakoid membrane. |
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Whats the purpose of the "head" in Chlorophyl A and B? |
Light absorbtion. |
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What happens when the antenna complex absorbs blue or red light? |
An e- gets excited and tranfers to a nearby chlorophyl molecule. |
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What happens when green light hits an antenna complex? |
Nothing. No resonance occurs |
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What is resonance in photosynthesis? |
Where e- transfer to nearby chlorophyl molecule. |
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What occurs in flourescence in photosynthesis? |
Photon excites an electron and the electron drops back down in energy. Releasing light and heat |
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What is a reaction center in chlorophyll? |
Its a special pigment where the e- gets excited and picked up. By either Pheophytin(photosystem II) or Ferrodoxin(photosystemI) |
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What is pheophytin and its role in photosystem II? |
Pheophytin is structurally the same as chlorophyll except it has no Mg molecule in its head. It accepts electrons and transports them to Plastoquinone(PQ) which then tranfers it to the Electron transport chain. |
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Which electron acceptor gets used in Photosystem II |
Pheophytin |
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Which electron acceptor is used in photosystem I |
Plastocyanin |
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What is plastquinone? |
A quinone(small hydrophobic molecule) that is lipid soluble and not anchored to a protien. |
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What is plastoquinones 1st function? |
Plastoquinones shuttles electrons from pheophytin to more electronegative molecules in the ETC(electron transport chain) including cytochrome. |
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What is plastoquinones 2nd function? |
Plastoquinone gathers protons after ETC transporting them to the lumen side of the thylakoid membrane lowering the pH of the lumen side of the thylakoid membrane. |
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What is the net result of ETC |
Like cellular resperation the ETC creates a proton gradient, which creates a proton motive force that pushes ATP synthase. |
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What is photophosphorylation? |
ATP synthase creating ATP from ADP+Pi in a chloroplast. |
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How does Photosystem II get electrons to excite for its inital step? |
Water gets oxidized producing this reaction 2H2O -> 4H + 4e + O2 the 4e go to the reaction center for photosystem II |
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Whats oxygenic photosynthesis? |
Organisms thatbproduce oxygen in photosystem II |
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Whats anoxygenic photosynthesis? |
A non oxygen producing organism. |
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Whats the end result of Photosystem II? |
ATP production through Photophosphorylation, and to transfer e- to plastocyanin |
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What is plastocyanin? |
Small diffusable protien. |
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What is Plastocyanins(PC) function? |
Picks up 1000 electrons amd delivers them to photosystem I/ replaces P700 electrons |
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What is the end result of photosystem I? |
2 NADPH |
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What is the enhancement effect? |
When Lights of wavelength 680 are shown only photosystem II works efficiently, while the other slows down. When wavelengtsh of 700 are shown its inversed with photosystem I working more efficiently. The enhanvement effect is when both lights are shown and they both produce at their maximum rate |
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What is cyclic photophosphorylation? |
Photosystem transports electrons back to ETC to help reduce CO2 and produce sugar. |
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Does cyclic photophosphorylation co exist with the Z scheme? |
Yes it does |
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What is the Z scheme? |
Its the pathway representation of events between photosystem II and I. |
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What is RuBP? |
Rubisco 1, 5 biphosphate. |
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What are the steps to the calvin cycle? |
1.Fixation 2.Reduction 3. Regeneration |
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What is fixation in the calvin cycle? |
The calvin cycle begins when CO2 reacts with RuBP. Fixes carbon and produces 2 molecules of 3 -phosphoglycerate |
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What is reduction phase in the calvin cycle? |
3-phosohoglycerate is phosphorylated by ATP and then reduced by electrons from NADPH. Producing glyceraldhyde-3-phosphate. (G3P) |
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What is G3P? |
Glyceraldhyde-3-phosohate |
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What is a byproduct of the reduction phase? |
Glucose and fructose. |
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What is the regeneration phase in the calvin cycle? |
Thenrest of the G3P keeps the cycle going by serving as the substrate for the third ohase in the cycle. |
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What is photorespiration? |
Consumes oxygen and produces CO2 |
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Whats the difference between photosynthesis and photoresperation? |
Photosynthesis uses Co2 for calvin cycle creating 2 3-phosphoglycerate While photoresperation produces one 3 phosphoglycerate(used in calvin cycle) and one 2-phosphoglycolate(releasing co2 using up ATP) |
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What does photoresperation do? |
It undoes photosynthesis. |
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When is photoresperation more likely to occur? |
When oxygen concentrations are high and CO2 concentrations are low. |
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What is C3, and C4 photosynthesis? |
When Co2 fixation occurs it produces a 4 carbon. Sugar. |
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What is PEP carboxylase? |
An enzyme that adds Carbon dioxide to RuBP |
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Difference between C4 and C3 plants? |
C3 plants have chloroplasts and rubisco in the mesophyll cells. |
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Mesophyll cells |
Are near the surface of the leaf |
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Steps of C4 plant |
Step 1:PEP carboxylase fixes CO2 in mesophyll cells Step 2: the 4 carbon organic acids, travel to the bundle sheathe cells through plasmodesmata. Step 3: 4 carbon organic acids release a CO2 molecule, rubisco uses a substrate to form a 3 phosohoglycerate. |
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What is CAM? |
Crassulacean acid metabolism |
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Whats the differemce between CAM plants and C3- C4 plants? |
C4 plants stockpile CO2 in cells where rubisco is not present- CAM plants store CO2 when rubisco is inactive. C4 plants use space to seperate its reactions CAM uses time to seperate them. |