Term
| What are the two separate but linked processes in photosynthesis? |
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Definition
The energy transformation of the light-dependent reactions and
The carbon dioxide reduction of the Calvin cycle |
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Term
In the presence of light
ATP and NADPH are produced by ? |
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Definition
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Term
| The reactions that produce sugar from carbon dioxide in the Calvin cycle are dependent on what? |
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Definition
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Term
| Reactions in the calvin cycle require what? |
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Definition
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Term
| What are the 3 phases of the calvin cycle? |
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Definition
| Fixation, reduction, and regeneration |
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Term
| In the calvin cycle, in the fixation phase C02 reacts with what? |
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Definition
| ribulose bisphosphate (RuBP) |
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Term
| In Fixation when CO2 reacts with ribulose bisphosphate (RuBP)what is produced? |
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Definition
| two 3-phosphoglycerate molecules |
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Term
| In the calvin cycle, in the reduction phase The 3-phosphoglycerate molecules are Phosphorylated by ? |
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Definition
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Term
| In the calvin cycle, in the reduction phase The 3-phosphoglycerate molecules are Phosphorylated by ATP and then reduced by? |
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Definition
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Term
| In the calvin cycle, in the reduction phase The 3-phosphoglycerate molecules are Phosphorylated by ATP and then reduced by NADPH producing? |
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Definition
| glyceraldehyde 3-phosphate (G3P) |
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Term
| In the calvin cycle, in the Regeneration phase the remaining G3P is used in ? |
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Definition
| reactions that regenerate RuBP |
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Term
| The calvin cycle of reactions occurs in the? |
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Definition
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Term
| One turn of the Calvin cycle fixes one molecule of ? |
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Definition
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Term
| How many turns in the Calvin Cycle are required To produce 1 molecule of G3P? |
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Definition
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Term
| The discovery of the Calvin cycle clarified what two things about phyotosynthesis? |
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Definition
| How the ATP and NADPH produced by light-capturing reactions allow cells to reduce CO2 to carbohydrate |
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Term
| The CO2-fixing enzyme is ? |
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Definition
| Ribulose 1,5-bisphosphate carboxylase/oxygenase KNOWN AS: (rubisco) |
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Term
| What organisms contain rubisco? |
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Definition
| photosynthetic organisms that use the Calvin cycle to fix carbon |
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Term
| What is the most abundant enzyme on earth? |
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Definition
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Term
| Rubisco is inefficient because? |
|
Definition
it catalyzes the addition of CO2 to RuBP
It also catalyzes the addition of O2 to RuBP |
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Term
| What molecules compete at the rubisco’s active sites? |
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Definition
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Term
| When 02 and CO2 compete at rubiscos active sites what is the result? |
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Definition
| Slows the rate of CO2 reduction |
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Term
| When O2 and RuBP react in rubisco’s active site one of the products undergoes a process called? |
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Definition
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Term
| What does photorespiration do to photosynthesis? |
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Definition
| it undoes it: It consumes energy and releases fixed CO2 |
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Term
| Carbon fixation is favored over photorespiration when? |
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Definition
CO2 concentration is high
O2 concentration is low |
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Term
What are stomata and what do they do?
(in an arnold voice) |
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Definition
| Are leaf structures where gas exchange occurs |
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Term
| The stomata has how many guard cells? |
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Definition
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Term
| What do the guard cells do? |
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Definition
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Term
| When a leaf’s CO2 concentration is low during photosynthesis what do the stomata do and why? |
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Definition
| Stomata open to allow atmospheric CO2 to diffuse into the leaf and its cells’ chloroplasts |
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Term
| A strong concentration gradient favoring entry of CO2 is maintained by the ? |
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Definition
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Term
| At what times are stomata open or closed? |
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Definition
open during day
closed at night |
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Term
| On hot, dry days, leaf cells do what? what does this action prevent? |
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Definition
Close the openings and halt photosynthesis
Or risk death from dehydration |
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Term
| Closing the stomata causes? |
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Definition
| CO2 delivery to stop, and thus photosynthesis, to stop |
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Term
| As the stomata close oxygen levels increase rates of? |
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Definition
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Term
| The c4 pathway is a mechanism for increasing? |
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Definition
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Term
| Where is the c4 pathway found primarily? |
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Definition
| mostly in plants from hot, dry habitats |
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Term
| the c4 pathway Limits the damaging effects of photorespiration by |
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Definition
| spatially separating carbon fixation and the Calvin cycle |
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Term
| In the c4 pathway, during carbon fixation, CO2 is incorporated in what that separates it from the C3 pathway? |
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Definition
4-carbon (C4) organic acids
Instead of 3-phosphoglycerate (performed by C3 plants) |
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Term
| The organisms that use crassulacean acid metabolism (CAM) are usually found where? |
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Definition
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Term
| In In crassulacean acid metabolism (CAM) what do plants do differently with their stomata? |
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Definition
Keep their stomata closed all day
Open them only at night |
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Term
| In crassulacean acid metabolism (CAM)carbon fixation and the calvin cycle are separeted by? |
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Definition
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Term
| How many and what are the steps are in the C4 calvin cycle? |
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Definition
3
1)PEP carboxylase fixes CO2
2)4-carbon organic acids produced travel
3)The four-carbon organic acids release a CO2 molecule |
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Term
| In step 3 of c4 calvin cycle what does rubisco do with the CO2? |
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Definition
uses to form 3-phosphoglycerate
Initiating the Calvin cycle |
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Term
| During the night, CAM plants take in CO2 and do what with it? |
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Definition
| Temporarily fix it into organic acids |
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Term
| During the day in CAM plantts, CO2 is released from the stored organic acids used where? |
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Definition
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Term
| C4 and CAM function as CO2 pumps to minimize? |
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Definition
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Term
| G3P molecules produced by the Calvin cycle are often used to make |
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Definition
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Term
| glucose and fructose can be combined to make? |
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Definition
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Term
| In photosynthesizing cells where sucrose is abundant what happens to Glucose ? |
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Definition
| Glucose is temporarily stored in the chloroplast as starch |
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Term
Because starch is not water soluble
It is broken down when? |
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Definition
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Term
| When starch is broken down at night what is it used for? |
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Definition
| to make more sucrose for transport throughout the plant |
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