Molecular Cell Biology — DU B. Sc. (Hons) Biochemistry Previous Year Question Papers

(b) Describe the major regulatory steps / stages of (c) How are proteins targeted to mitochondrial matrix? What happens to protein targeting if a drug is used that abolishes mitochondrial membrane potential. (6,4,5) 6. Write short notes on the following: (b) UPR pathways in ER 2. There are 6 questions. 1. (a) Explain the following statements: (i) DNA is replicated only once during cell cycle. (i) Cancer patients undergoing chemotherapy become immunocompromised. (iii) Weel kinase mutant in fission yeast cells are smaller in size than normal daughter cells. (vi) Glycolipids are always present on the outer leaflet of the cell membrane. (b) Write the scientific contribution of the following scientists: (i) George Palade (ii) Robert Horvitz 2. Differentiate between the following : (i) Protooncogenes and Tumor suppressor gene (iii) COP I and clathrin coated vesicles 3. (a) Discuss how Cdkl/ Cyclin B complex initiates the onset of M phase. (b) How the GPCR signaling will be affected if the (c) Explain various modifications that takes place in the proteins once it enters the ER lumen. (d) What is the role of Cip/kip and ink-4 family of protein in cell cycle progression? (5,3,5,3) 4. (a) Discuss the mechanism by which a mitotic cell ensures the faithful segregation of chromosomes to opposite spindle poles of the cell. (b) What is the role of second messengers in signal transduction? Briefly discuss with two examples. (c) Describe different stages of cancer development with the help of a diagram. (5,5,5) 5. (a) Discuss the mechanism of MAPK signaling pathway and how does the dysregulation of this pathway lead to cancer?