Student Number: a) Indicate which, if any, of the six proteins would be found in these three fractions.

Transcription

1 Name: Student Number: April 23, 2009, 9:00 AM -12:00 PM Page 1 (of 4) Biochemistry II Laboratory Section Final Examination Examiner: Dr. J. Galka 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 A tissue extract containing six proteins, K, L, M, N, O, P, was dissolved in 0.15M phosphate buffer, ph 5.5. The molecular weights and isoelectric points of the proteins are shown below: Protein MW pi K 107, L 35, M 173, N 96, O 185, P 71, The tissue extract was placed on a CM-Sephadex column and subsequently eluted with three buffers to give three fractions (1A-3A). Fraction 1A was eluted at ph 5.5, 2A was eluted at ph 6.5, and 3A was eluted at ph 9.0. a) Indicate which, if any, of the six proteins would be found in these three fractions. Fraction 1A Fraction 2A Fraction 3A b) Give reasons to explain your answers above, including a brief description of how the CM-Sephadex column functions, and why the proteins behave as they do.

2 April 23, 2009, 9:00 AM -12:00 PM Page 2 (of 4) Biochemistry II Laboratory Section Final Examination Examiner: Dr. J. Galka 4 b) Fraction 3A from the first column was then applied to a Sephadex G-100 column (Fractionation range MW 4, ,000) and eluted with buffer, ph 9.0, to give twelve fractions. Fractions 1B to 12B. Only two of these fractions contained protein, 1B and 6B. (i) Indicate which if any of the six proteins would be found in these fractions. Fraction 1B Fraction 6B (ii) Give reasons to explain the answer given above including a brief description of how the column functions and why the proteins behave as they do on the column Use a figure to illustrate the staining sequence used in the lab this term for lactate dehydrogenase.

3 April 23, 2009, 9:00 AM -12:00 PM Page 3 (of 4) Biochemistry II Laboratory Section Final Examination Examiner: Dr. J. Galka 5 3. Briefly describe the chemical assay used in the lab this term for lysozyme. Your answer should indicate the reagents used and their mode of action, however concentrations and volumes of these reagents are not required.

4 April 23, 2009, 9:00 AM -12:00 PM Page 4 (of 4) Biochemistry II Laboratory Section Final Examination Examiner: Dr. J. Galka 7 4. Use a flow chart to outline the experimental procedure used in the lab this term to isolate DNA, RNA and protein from liver homogenate. The names of the reagents used must be included and their purpose must be indicated on the chart, however concentrations and volumes of these reagents are not required.

5 Name: Student Number: April 23, 2009, 9:00 AM -12:00 PM Page 1 (of 4) Biochemistry II Lecture Section Final Examination Examiners: Drs. J. Stetefeld, P. Loewen 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 Using structural formulae and the names of compounds, enzymes and coenzymes, as well as diagrams, describe the mechanism by which changes in adrenalin levels in the blood affect the inter-conversion of glycogen and glucose-1-phosphate Describe how equilibrium centrifugation in a CsCl solution was used as a tool to study DNA replication and the conclusions that arose from that work. Who are the researchers associated with the work?

6 April 23, 2009, 9:00 AM -12:00 PM Page 2 (of 4) Biochemistry II Lecture Section Final Examination Examiners: Drs. J. Stetefeld, P. Loewen The final three codons in an open reading frame on a mrna encoding a 50 amino acid protein are AGA- CAA-UAA (AGA encodes Arg and CAA encodes Gln). Using diagrams including the structures of the amino acids describe the process in the ribosome including all necessary protein factors by which the final peptide bond of the protein is formed between Gln and the peptide and how the finished protein is released Using diagrams, describe the process by which light energy is captured in chemical form required for CO 2 fixation. Use this answer to calculate how much light energy is required to fix one CO 2 into organic form as glyceraldehyde-3-phosphate.

7 April 23, 2009, 9:00 AM -12:00 PM Page 3 (of 4) Biochemistry II Lecture Section Final Examination Examiners: Drs. J. Stetefeld, P. Loewen Using structural formulae and the names of compounds, enzymes and coenzymes, describe the series of reactions required to synthesize 2'-deoxyribothymidine-5'-monophosphate starting with the amino acids glutamine, serine and aspartate. Assume an abundant supply of energy and CO Using diagrams, structural formulae of all intermediates and the names of enzymes and coenzymes, describe the reactions that fix nitrogen gas into ammonia starting with pyruvate as the energy source.

8 April 23, 2009, 9:00 AM -12:00 PM Page 4 (of 4) Biochemistry II Lecture Section Final Examination Examiners: Drs. J. Stetefeld, P. Loewen 9 7. Using structural formulae and the names of all compounds, enzymes and coenzymes describe the reactions that would convert an excess of aspartate into palmitoleic acid and urea Using structural formulae and compound, enzyme and coenzyme names, describe the series of reactions by which a molecule of butyric acid would be converted into threonine.