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Unformatted text preview: Cell Biology / Cell Biochemistry BIOL 4374 / BCHS 4313 Exam 4 Dec 2, 2009 Read each question carefully . Chose the single best answer to each of the following questions. In some cases, key words are emphasized in bold italics font 1. Which of the following is false regarding gap junctions? a. they are formed by proteins called connexins b. eight protein subunits form a single connexon hemichannel c. connexon hemichannels on adjacent cells associate to form the functional gap junction d. calcium and small metabolites can pass through gap junctions e. all of the above are true regarding gap junctions 2. Which of the following cell-cell junctions is responsible for preventing the diffusion of solutes between apical and basolateral extracellular compartments in epithelial tissues? a. tight junctions b. adherens junctions c. desmosomes d. hemidesmosomes e. gap junctions 3. Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with intermediate filaments? a. tight junctions b. adherens junctions c. desmosomes d. hemidesmosomes e. gap junctions 4. Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with actin filaments? a. tight junctions b. adherens junctions c. desmosomes d. hemidesmosomes e. gap junctions 5. Which of the following is NOT a component of the basal lamina. a. laminin b. collagen c. proteoglycans d. fibronectin e. all of the above are components of the basal lamina 6. Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial sheet? a. adherens junctions tight junctions gap junctions desmosomes b. adherens junctions tight junctions desmosomes gap junctions c. tight junctions desmosomes adherens junctions gap junctions d. tight junctions adherens junctions gap junctions desmosomes e. tight junctions adherens junctions desmosomes gap junctions 7. Which of the following cell junctions does NOT include a cytoskeletal component? a. tight junctions b. adherens junctions c. desmosomes d. hemidesmosomes e. all cell junctions include cytoskeletal components 8. Which of the following is false regarding cadherins? a. they form homophilic interactions b. binding affinity is reduced by high extracellular calcium concentration c. members of the catenin protein family link them to cytoskeletal proteins d. they exclusively form cell-cell junctions e. all of the above are true regarding cadherins 9. S-Cdk complex prevents multiple DNA replication events by phosphorylating which of the following? a. M-Cdk b. cdc6 c. origin of replication complex d. p21 e. none of the above 10. The SMC protein complexes that gather and organize DNA strands into chromosomes are called a. gatherins b. cohesins c. compactins d. condensins e. none of the above 11. Which of the following proteins is NOT phosphorylated by M-Cdk?...
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This note was uploaded on 10/05/2010 for the course BCHS 3305 taught by Professor Briggs during the Spring '10 term at University of Houston-Victoria.
- Spring '10