Question
CELL BIO: Please answer as many as you can. I need them to be them 100% correct. if you are at all unsure, please skip it. i dont need an explanation. thank you .
even though answers are circled, Im notsure if theyre right or not
Exam 4 c They always activate target proteins missin 11 What do kinases do? a. They phosphorylate target proteins b. They dephosphorylate target proteins d. They form cAMP 12. Signal transduction cascades may perform which of the Relay the signal to the appropriate location in t o. he cell b. I ntegrate and unify several signal transduction cascades Amplify the signal c. Distribute the signal to multiple effector proteins Any or all of the above e. 13, Which of the following is not true regarding GTP-binding proteins c. They are active when they are bound to G d. They are inactive when bound to GDP -a. They can act as GTPases b. They can convert GDP to GTP 14. Ion channel-coupled receptors a. Are very fast acting b. Are common in neuronal signaling . Are usually activated by extracellular ligand binding d. Ail of the above 15. G-Protein-coupled receptors activate G proteins a. By causing them to release GDP and bind to GTP by causing 2 G-proteins to dimerize c. By causing them to hydrolyze GTP to GDP d. By causing them to phosphorylate GDP to GTP 16. When a G-protein become active The G-protein detaches from the membrane a. b. The G-protein phosphorylate the target enzyme . The G-protein-coupled receptor gets cleaved The alpha and beta/gamma subunits of the G-protein disassemble 17. Which of the following is not true regarding Adenylate cyclase? a. It acts to amplify the original signal b It uses ADP as its substrate It is activated by G-proteins d. It catalyzes the formation of the second messenger molecule cAMP 8. Which of the following is the main target of cAMP? (i.e. who does cAMP activate?) a. Adenylate cyclase C. Ras d. MAP-Kinase b.) Protein Kinase A (PKA) 19. Which of the following is not true regarding enzyme-coupled receptors? a. They often function in signal transduction cascades involved in cell growth, survival, differentiation or proliferation b. Activation of enzyme-coupled receptors generally turns on serine kinase activity They are monomers when they are inactive Ligand-binding causes the enzyme coupled receptors to dimerize or oligomerize 20. Which of the following is a signaling intermediate typically found in enzyme-coupled signal transduction cascades? a. Adenylate cyclase b. Ras c. Protein Kinase A (PKA) d. CAMP 21. Which of the following is not true regarding Ras? a. Ras is responsible for the eventual activation of MAP-kinase b. Ras is activated by binding to GTP c. Ras directly activates MAP-kinase kinase kinase d. Ras is phosphorylated by MAP-kinase kinase
Explanation / Answer
11. a
12. e
13. b
14. d
15. a
16. d
17. b
18.b
19. b
20. b
21. d
22. d
23. c
24. b
25. c
26.a
27. c
28. a
29. c
30. e
31. d
32. d
33. b
34. e
35.a
