Chapter 18: Cell Signaling

Question 1

What is the function of protein phosphatases in signal transduction?

A.Removing phosphate groups from proteins;

B.Phosphorylating methionine;

C.cAMP generation;

D.Chromatin acetylation;

E.Phosphorylating tyrosine kinase receptors.

Answer 1

A.Removing phosphate groups from proteins.

The protein phosphatases are enzymes that remove the phosphate group from proteins by the release of water.

Question 2

Which of the following is NOT a mechanism for increasing the specificity of a response to a cellular signal?

a- using multiple receptors for the same signaling molecule

b- using multiple signaling molecures for the same receptor

c- converging several different signaling molecules ton a single cell

d- diverging an amplified signal into multiple intracellular targets

e- modulating one singaling pathway by overlapping a second pathway

Answer 2

b- using multiple signalling molecules for same receptor

Because one signalling molecule has to interact with particular specific receptor. Different molecules on same receptor cannot.