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Topic: Photosynthesis/Calvin Cycle  (Read 20091 times)

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Offline Jazzified

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Photosynthesis/Calvin Cycle
« on: October 17, 2007, 10:12:08 PM »
I have 10 multiple choice problems that I worked on, and can I get my answers checked?  My answers are bolded.  Thanks.

1. Which of the following is (are) true of the enzyme ribulose bisphosphate carboxylase?
a. It participates in the Calvin cycle.    
b. It catalyzes a phosphorylation reaction.    
c. It has an affinity for both O2 (oxygen) and CO2 (carbon dioxide).    
d. a) and c) are true.    
e. a), b), and c) are true.

2.  Plants that fix CO2 into organic acids at night when the stomata are open and carry out the Calvin cycle during the day when the stomata are closed are called
a. C3 plants.    
b. C4 plants.    
c. CAM plants.    
d. B and C only.    
e. A, B, and C

3.  Why are C4 plants able to photosynthesize with no apparent photorespiration?
a. They do not participate in the Calvin cycle.    
b. They use PEP carboxylase to initially fix CO2.    
c. They are adapted to cold, wet climates.    
d. They conserve water more efficiently.    
e. They exclude oxygen from their tissues.

4.  Both mitochondria and chloroplasts _____.
a. Use a proton (H+) gradient and the ATP synthase to produce ATP    
b. Obtain electrons from water    
c. Reduce NAD+, forming NADP    
d. Release oxygen as a by-product    
e. Are surrounded by a single membrane

5.  During photosynthesis in a eukaryotic cell, a high proton (H+) concentration is formed in the ______.
a. space between the outer and inner chloroplast membranes    
b. thylakoid space (compartment)    
c. chloroplast stroma    
d. stomata    
e. mitochondrial matrix

6.  Which of the following statement is TRUE in describing the redox reactions of photosynthesis?
a. Water is reduced and carbon dioxide is oxidized    
b. Both water and carbon dioxide are reduced    
c. Both water and carbon dioxide are oxidized    
d. Carbon dioxide is reduced and water is oxidized    
e. Sugar is oxidized

7.  During photosynthesis in chloroplasts, O2 (oxygen) is produced from ______ via reactions associated with ______.
a. CO2 (carbon dioxide) ... photosystem II    
b. CO2 (carbon dioxide) ... Calvin cycle    
c. H2O (water) ... photosystem II    
d. H2O (water) ... photosystem I    
e. CO2 (carbon dioxide) ... photosystem I

8.  NADP+ plays an important role in photosynthesis because ___
a. It assists chlorophyll in capturing light.    
b. It acts as the primary electron acceptor in the photosystems.    
c. As part of the electron transport chain, it manufactures ATP.    
d. It assists photosystem II in the splitting of water.    
e. It is reduced and then carries electrons to the Calvin cycle.

9.  The Calvin cycle requires all of these chemicals to proceed except ___.
a. ATP    
b. NADPH    
c. Carbon Dioxide    
d. RuBP (5-carbon CO2 acceptor)    
e. Oxygen

10.  What are the substrates (normal reactants) for the enzyme RuBP carboxylase?
a. CO2 and O2 (carbon dioxide and oxygen)    
b. CO2 (carbon dioxide) and glucose    
c. ATP and NADPH    
d. G3P, glucose, and CO2 (carbon dioxide)    
e. CO2 (carbon dioxide) and ATP

Offline Yggdrasil

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Re: Photosynthesis/Calvin Cycle
« Reply #1 on: October 17, 2007, 11:55:03 PM »
All of them look ok to me.  For the last one, none of them seem right (since RuBP is a substrate of Rubisco), but a looks most correct.

Offline Jazzified

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Re: Photosynthesis/Calvin Cycle
« Reply #2 on: October 18, 2007, 12:15:44 AM »
Thanks, Yggdrasil!
« Last Edit: October 19, 2007, 09:47:23 PM by FlipStyle1308 »

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