Download Spring 1989 Zoology Exam: Protein Synthesis, Endocytosis, and Membrane Potentials and more Exams Cell Biology in PDF only on Docsity! Name Colombini et al Lab Section _ ________ Spring 1989 (which day)? Examination II of III INSTRUCTIONS: 1. Print your name on each page of the exam. 2. Read the directions at the beginning of each section. 3. Write legibly and in iiik (if you wish to be eligible for regrade). 4. Do not write on the back of the pages 5. Good luck! Question (1) _______ out of 15 (2) _______ out of 35 (3) _______ out of 15 (4) _______ out of 10 (5) _______ out of 15 (6) _______ out of 20 (7) _______ out of 15 (8) _______ out of 15 (9) _______ out of 10 Total out of 150 Zool. 211 Exam Questions 1. Synthesis of proteins destined for secretion. Given the following list: (15 pts.) A. Clathrin B. 5' end C. 3' end D. amino end E. COO end F. Docking protein G. Ribophorin H. SRP I. Initiation factor Using the list given above, indicate with a letter (A through I) the appropriate choice for each of the following statements. Only one letter per statement. This is a binding protein specific for the large ribosomal subunlt. Answer: ____ SRP binds to this protein. Answer: ____ The signal peptide binds to this complex. Answer: A signal peptide would be coded for by nucleotides present on that end of a mRNA. Answer: _____ Amino acids present on the carboxylic end of a protein would be coded for by nucleotides present on that end of a mRNA. Answer: ______ A cap site would be located on that end of a mRNA molecule. Answer: ____ A poly A sequence would be located on that end of a mRNA molecule. Answer: 5) Mitochondrial energy production: how does the utilization of oxygen lead to ADP phosphorylation to form ATP? (give the overall mode of energy transductiori....leave out the details) (15 pts.) 6) With regard to the action potential that propagates in an axon, (20 pts.) a) how rapidly does the membrane depolarize? (approx. in sec.) b) what determines the rate of depolarization? (disregard temp, and press.) c) what determines the potential reached at the peak of the action potential d) what directly powers the action potential? 7) In lab, a sciatic nerve was stimulated extracellularly and the resulting signal detected some distance away. When the stimulus intensity was reduced what happened to the intensity of the recorded signal? How does this fit with the statement that action potentials are "all-or-none"? Explain (15 pts.) 8) With regard to skeletal muscle, what structure (15 pts.) a) delivers the action potential to the myofibrils? b) stores Ca+ * inside the muscle cell? c) forms the cross-bridges? d) binds Ca++ ? e) hydrolyzes ATP resulting in filament sliding? 9) Diagram the steps in rnicrofilament assembly from individual subunits to the assembled filament. (10 pts.)
