Week 1 Formative questions(1)

Dr. Eisenmann - Introduction to Cell Biology 1. From the lumen of the rough endoplasmic reticulum, proteins to be secreted move directly to the A. extracellular space. B. mitochondria. C. golgi apparatus. D. smooth endoplasmic reticulum. E. cytoplasm. 2. A medical student is investigating a response of white blood cells to the bacterial infection. He starts with microscopic investigation of the paronychia (nail infection) in a 55-year-old man. The first thing he sees is a leucocyte propelling the membrane at its leading edge. The student is fascinated and asks you how it happens. Question: How will you explain phagocytosis in terms of basic active mechanism underlying this first movement of the leading edge? A. Traction Force B. Stall Force C. Actin Polymerization D. Active Transport E. Retraction Dr. Williams - Introduction to Proteins: Part 1 3. Hydrogen bonds are usually _________ than covalent bonds (choose correct answer for blank) A. longer B. shorter C. equal in length D. stronger 4. What charged group(s) is(are) present in glycine at a neutral pH? A. NH 3 + B. COO - C. NH 2 + D. A and B E. A, B, and C 1

Dr. Williams - Introduction to Proteins: Part 2 5. The configuration of most alpha-carbon R groups of amino acids linked in a peptide bond are A. cis B. circular C. parallel D. trans E. perpendicular 6. The pathogenesis of prion disease is attributed to a change in the secondary structure of the prion protein, leading to irreversible aggregation, resulting in neurodegeneration and eventual death. Secondary structure of polypeptide chains A. is the spatial arrangement of amino acid residues that are far apart in sequence. B. cannot be predicted based upon amino acid sequence. C. consist primarily of two regularly repeating (periodic) secondary structures. D. is none of the above. Dr. Williams - Introduction to Proteins: Part 3 7. How do proteins find the correct conformation? A. Cooperative transition B. Cumulative selection by progressive stabilization of intermediates C. Random interactions D. A, B and C E. A and B 8. When purifying enzymes, the assay for specific activity is often based on A. ultracentrifugation. B. catalytic activity (measurement of end product). C. pH. D. temperature changes. E. salt changes. 2

ANSWER KEY Eisenmann 1. C 2. C Williams 3. A 4. D 5. D 6. C 7. E 8. B Li 9. C 10.E 4