MCB 259: PLANT PHYSIOLOGY 1998, Quiz 7 - November 18, 1996
Name (please print):



1What does the abbreviation RubisCO stand for?

2.In the entrance reaction (=carboxylation) to the Calvin cycle the CO2 molecule is added to a sugar phosphate molecule. What is the name of this sugar phosphate and how many carbons does this sugar contain?
Name: _____________________________________ Number of C's:___

3.Which enzyme catalyses the entrance reaction of the photorespiration?

4.What is the first detectable product after carboxylation of ribulose-bis-phosphate by RubisCO? How many carbons does this molecule have?
Name: Number of C's:

5.In the subsequent reactions of the Calvin cycle ATP and NADPH2 are used to modify this compound (see question 4). These reactions lead to :
A) The oxidation of this compound
B) The reduction of this compound
C) The carboxylation of this compound

6. Sugar structure and function:
- glucose is a pentose (correct/incorrect)
- glucose is a hexose (correct/incorrect)
- sucrose is a monosaccharide (correct/incorrect)
- fructose is an aldose (correct/incorrect)
- ribose is a pentose (correct/incorrect)
- in dilute watery solution ribose can be present as a pyranose (correct/incorrect)
- glucose is a ketose (correct/incorrect)
- sucrose consists of two glucose molecules linked via an alpha 1-4-glycosidic link   (correct/incorrect)
- sucrose consists of glucose and fructose linked via their reducing ends (correct/incorrect)
- Sucrose is a reducing sugar (correct/incorrect)

7. Where do the reactions of Calvin cycle take place
A) in the lumen of the thylacoid
B) in the stroma of the chloroplast
C) in the cytoplasm outside the chloroplast

8. RubisCO in higher plants consists of 4 small and 4 large subunits.
A) These subunits are all encoded in the chloroplast genome
B) These subunits are encoded in the nuclear genome, they are assembled in the cytoplasm, the assembled octamer is transported into the chloroplasts.
C) the small subunits are nuclear encoded, the large subunits are plastid encoded.

9. Which is the most abundant soluble protein
A) Chaperones, B) RubisCO, C) cF-ATPases


10. In plants the Calvin cycle (also called the dark reaction) is regulated so that itís key enzymes are turned off in the absence of light. Correct/incorrect