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Cards In This Set
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Structure of the chloroplast Where does light reaction and calvin cycle take place?
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 Extra membrane to allow for gradient Thylakoid--Light Reaction Stroma-- Calvin Cycle |
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At the end of the light reaction, where is the energy derived from the photons stored?
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Stored as NADPH and ATP
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Summarize reactions occurring in the three phases of the Calvin cycle
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Fixation: -carbon is fixed out of the atmosphere by rubisco to a 5 carbon RuBP molecules -it is broken into 2 3-Carbon atoms (3-phosphoglycerate)
Reduction:-add ATP and NADPH to create G3P which goes on to become glucose or used for regeneration Regeneration: G3P regenerated by RuBP (requires ATP) |
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Why is RUBISCO the most important enzyme on earth?
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Because it fixates carbon out of the air -one of least efficient enzyme
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What does fixed mean?
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Extracting Carbon Dioxide and putting it in a usable form
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How does the current atmosphere differ from that inw hich potohsytehesis evlove?
How does the earth atmosphere reduce the efficiency of rubsio? |
Oxygen levels used to be much lower and CO2 levels used to be much higher
Switched-as CO2 dropped that is when photosynthesis evolved Because oxygen can fit into binding site of rubisco reduces the efficiency--uses oxygen instead of CO2 which competes at enzymes active sites which slows the rate of CO2 reduction HAD TO EVOLVE WAYS TO AVOID PHOTORESPIRATION ( fixated oxygen not carbon) |
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In what two ways does photorespiration drain energy from the plant?
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1. Uses energy2. Loss of Fixed carbon
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Describe the interior of a typical leaf. How do gasses move from the atmosphere to the interior of the leaf?
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Atmosphere gases go through the stomata into the air space where the mesophyll cells fix carbon out of the atmosphere
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What are the advantages and disadvantages to a plant of OPENING stomata? and of CLOSING stomata
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OPEN:-gain carbon dioxide-lose oxygen (PRO)-lose water (CON)
CLOSING-not gain carbon dioxide-don't lose oxygen (CON)-don't lose water (PRO) |
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C4 and CAM photosynthesis are described as "CO2 pumps" How do these forms of photosynthesis differ from C3 and why should they be characterized as "pumps"?
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Function as pumps to minimize the amount of photorespiration that occurs when stomata are closed and CO2 cannot diffuse directly from atmosphere
-process is different and how CO2 is moved through cell different and when its allowed to move into cell |
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In C4 and CAM plants rubisco always operates under conditions of elevated CO2
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In C4 and CAM plants rubisco always operates under conditions of elevated CO2
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Predict the relative success of C3, C4 and CAM plant in a..1. cool2. wet environment 3. hot dry environment
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C31. good 2. good3. bad
C41. ok (less good-requires energy)2. ok (less good-requires energy)3. good CAM1. ok (less good-requires energy)2. ok (less good-requires energy)3. good |
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What happens to the sugar that is produced by photosynthesis?
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1. Respiration2. used in cell walls/cellulose3. storage4. structure
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C4
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-CO2 air and O2 come in
-fixed in mesophyll by pep carboxylase-through plasmodesmata into bundle sheath-go through mitochondria where C4 is converted to C3-C3 regenerated-CO2 goes to chloroplasts where it is converted to starch FIXES MORE CARBON |
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CAM
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-stomata open at night and closed during the day -fixes carbon at night-PEP Carboxylase -C4 goes into vacuole where it is stored until day time-C4 is converted to C3 -CO2 goes to chloroplasts where it is converted to starch
prevents water loss by stomata being open at night |
