#Question id: 1124
#Unit 4. Cell Communication and Cell Signaling
Which of the following is (are) intracellular second messengers?
a. Ca2+ b. cAMP c. epinephrine
d. protein kinase A e. protein kinase C
#Question id: 1125
#Unit 4. Cell Communication and Cell Signaling
Examples of G protein–coupled receptors include
a. rhodopsin receptor. b. β-adrenergic receptor.
c. insulin receptor. d. acetylcholine receptor.
#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