#Question id: 1126
#Unit 4. Cell Communication and Cell Signaling
Which of the following statement(s) is (are) true of the α subunit of a G protein?
a. It physically associates with the receptor.
b. It binds GDP.
c. It binds GTP.
d. It is a transmembrane protein.
#Question id: 1127
#Unit 4. Cell Communication and Cell Signaling
Which of the following steps does not occur after acetylcholine binds to the muscarinic acetylcholine receptor in heart muscle cells?
#Question id: 1128
#Unit 4. Cell Communication and Cell Signaling
During the epinephrine stimulated conversion of glycogen to glucose 1-phosphate, which of the following steps involves protein phosphorylation?
a. inactivation of glycogen synthase b. activation of protein kinase A
c. activation of adenylyl cyclise d. activation of glycogen phosphorylase
#Question id: 1129
#Unit 4. Cell Communication and Cell Signaling
Which of the following plays a role in the relaxation of smooth muscle cells by nitric oxide?
a. cGMP b. protein kinase A c. protein kinase G d. guanylyl cyclise
#Question id: 1130
#Unit 4. Cell Communication and Cell Signaling
In muscle cells, glycogen phosphorylase kinase is activated by
a. Ca2+. b. diacylglycerol. c. nitric oxide. d. protein kinase A.
#Question id: 1131
#Unit 4. Cell Communication and Cell Signaling
Which of the following function(s) as an inhibitor of TGFβ signal transduction?
a. R-Smad b. I-Smad c. Co-Smad d. Ski e. SnoN