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Student Number: __________________
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THE UNIVERSITY OF MANITOBA
April 13, 2012, 1:30 PM - 4:30 PM
Page 1 (of 5)
CHEM/MBIO 2370 Final Examination
Examiners: Drs. E. Nichols and P. Loewen
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1. Answer ALL questions in the space provided.
2. The back side of each page may be used for your answer or for preliminary work.
3. Questions to invigilators about the exam will NOT be answered.
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Marks
15 1. (a) Write the overall equation describing photosynthesis as it occurs in plants. How does it differ in green
sulfur bacteria? Indicate the electron donors and electron acceptors in your answer.
(b) What is a Hill reagent and what is the Hill reagent employed in vivo by plants?
(c) Write out a balanced reaction showing how the Hill reagent is modified in the light reactions in
chloroplasts.
(d) How does light energy make electron transfer possible at the atomic level?
(e) Using diagrams and the names of all intermediates, describe the process that couples light energy to
reduced electron carrier and ATP formation in the thylakoid membrane.
5
2. Using structural formulae and compound names, write out the equations of the two reactions catalyzed by
ribulose bisphosphate carboxylase using either CO2 or O2 as substrates. Given the KM = 350 µM for O2 and
the KM = 9 µM for CO2, which reaction will be operating at closer to its Vmax when [O2] = 250 µM and
[CO2] = 10 µM and why?
THE UNIVERSITY OF MANITOBA
April 13, 2012, 1:30 PM - 4:30 PM
Page 2 (of 5)
CHEM/MBIO 2370 Final Examination
Examiners: Drs. E. Nichols and P. Loewen
_______________________________________________________________________________________
Marks
20
3. Using structural formulae and compound, coenzyme and enzyme names, outline the process by which
phenylalanine is completely degraded to 9 CO2 and NH3. Calculate the energy yield as ATP equivalents per
phenylalanine assuming an active electron transport chain. Ignore dihydrobiopterin reduction.
THE UNIVERSITY OF MANITOBA
April 13, 2012, 1:30 PM - 4:30 PM
Page 3 (of 5)
CHEM/MBIO 2370 Final Examination
Examiners: Drs. E. Nichols and P. Loewen
_______________________________________________________________________________________
Marks
10
10
4. Using structural formulae and compound, coenzyme and enzyme names, outline the process by which 3phosphoglycerate is converted into ribulose-5-phosphate in the Calvin Cycle.
5. Using structural formulae and compound, coenzyme and enzyme names, outline the process by which
acetyl CoA and dihydroxyacetone phosphate are converted into tripalmitoyl glyceride. Assume an abundant
supply of ATP, CO2, NADPH and coenzyme A.
THE UNIVERSITY OF MANITOBA
April 13, 2012, 1:30 PM - 4:30 PM
Page 4 (of 5)
CHEM/MBIO 2370 Final Examination
Examiners: Drs. E. Nichols and P. Loewen
_______________________________________________________________________________________
Marks
10
6. Using structural formulae and compound, coenzyme and enzyme names, outline the process by which
deoxycytidine triphosphate is synthesized from ribose-5-phosphate, aspartate, CO2, ATP, FAD and
glutamine.
10
7. Using structural formulae and compound, coenzyme and enzyme names, outline the process by which
isoleucine is synthesized from oxaloacetate, glutamate, ATP and NADPH.
THE UNIVERSITY OF MANITOBA
April 13, 2012, 1:30 PM - 4:30 PM
Page 5 (of 5)
CHEM/MBIO 2370 Final Examination
Examiners: Drs. E. Nichols and P. Loewen
_______________________________________________________________________________________
Marks
20
3. Using diagrams, structures and names of compounds, enzymes and coenzymes, describe:
(a) how the "wobble" in Crick's Wobble Hypothesis reduces the number of tRNAs required by a cell;
(b) how catabolite repression influences expression of the lac operon;
(c) the role of elongation factors in the translation process;
(d) why bacteria but not humans can convert fats into carbohydrate;
(e) why C4 plants have a growth advantage.