Devita, Hellman, and Rosenberg's Cancer

LWBK1006-01 LWW-Govindan-Review November 24, 2011 11:17

Chapter 1•Molecular Biology of Cancer Part 1 7

Question 1.33. Which of the following is FALSE about receptor phosphotyrosine phos-

phatases?

A. No true ligands for these have been described.

B. They always function to antagonize tyrosine kinases.

C. Activation could increase intracellular phosphorylation under certain

circumstances.

D. Most receptor phosphatases contain two catalytic domains.

Question 1.34. Which of the following statement regarding the epigenetic process is

FALSE?

A. Most CpG islands are not methylated.

B. The level of acetylation correlates with the level of gene expression.

C. The CpG dinucleotides are symmetrically distributed in the human

DNA.

D. The X-chromosome inactivation occurs through methylation.

Question 1.35. Which of the following is TRUE about GTP-binding proteins?

A. GDP hydrolysis leads to a conformational change.

B. All are lipid modified.

C. Ras-like proteins exist in trimers.

D. Gai stimulates adenylate cyclase.

Question 1.36. Protein kinase A is the target of which of the following second messengers?

A. Cyclic adenosine monophosphate (cAMP).

B. Phospholipase C

C. Diacylglycerol

D. B and C

Question 1.37. Regulation of protein levels can be affected by:

A. Signal transduction

B. Translation

C. Proteolysis

D. All of the above

Question 1.38. Inhibition of the addition of a lipid moiety to Ras would potentially lead

to:

A. Increase in activation Raf

B. Decrease in cell proliferation

C. Increase in activation of MEK

D. A and C