Cell Bio Exam 3 Version A Key
question well answered graded A+
2025/2026
Which amino acid is NOT mainly phosphorylated by a protein kinase?
A. Threonine
B. serine
C. tyrosine
D. lysine - correct answer ✔✔lysine
Which of the following proteins would tend to increase or prolong the amound of signal
produced by a GTP-binding protein in its active state?
A. A protein that decreases the GTPase activity of the protein
B. A protein that prevents the binding of GTP
C. A protein that increases the release of GDP
D. Both A and C would increase or prolong the signaling activity of the protein - correct answer
✔✔Both A and C would increase or prolong the signaling activity of the protein
Which of the following does not activate nuclear receptors?
A. acetylcholine
B. estradiol
C. thyroxine
D. testosterone - correct answer ✔✔acetylcholine
, Which of the following is not a property of signaling through GPCRs?
A. activation of heterotrimeric G proteins
B. GTPase activity of the Gα subunit
C. activation of an effector enzyme (eg, adenylyl cyclase)
D. receptor dimerization - correct answer ✔✔receptor dimerization
Which of the following is not a property of receptor serine/threonine kinases?
A. conversion of GTP to cGMP
B. tetramerization
C. transphosphorylation
D. involvement of two receptor types (ie, type I and type II) - correct answer ✔✔conversion of
GTP to cGMP
In the Na+/K+ pump, the energy required to move Na+ ions against its gradient is coupled to the
__________ . - correct answer ✔✔hydrolysis of ATP
Which of the following are present in the nucleus?
A. phospholipase C
B. receptor tyrosine kinases
C. G protein coupled receptors
D. all of the answers are correct - correct answer ✔✔all of the answers are correct
Genistein is a drug that inhibits tyrosine kinases. Which of the following cellular events is
susceptible to inhibition by genistein?
A. Translocation of newly synthesized phospholipids by "flippase" enzymes.
B. Binding of Grb2 to SOS protein
C. leakage of K+ through K+ channels
question well answered graded A+
2025/2026
Which amino acid is NOT mainly phosphorylated by a protein kinase?
A. Threonine
B. serine
C. tyrosine
D. lysine - correct answer ✔✔lysine
Which of the following proteins would tend to increase or prolong the amound of signal
produced by a GTP-binding protein in its active state?
A. A protein that decreases the GTPase activity of the protein
B. A protein that prevents the binding of GTP
C. A protein that increases the release of GDP
D. Both A and C would increase or prolong the signaling activity of the protein - correct answer
✔✔Both A and C would increase or prolong the signaling activity of the protein
Which of the following does not activate nuclear receptors?
A. acetylcholine
B. estradiol
C. thyroxine
D. testosterone - correct answer ✔✔acetylcholine
, Which of the following is not a property of signaling through GPCRs?
A. activation of heterotrimeric G proteins
B. GTPase activity of the Gα subunit
C. activation of an effector enzyme (eg, adenylyl cyclase)
D. receptor dimerization - correct answer ✔✔receptor dimerization
Which of the following is not a property of receptor serine/threonine kinases?
A. conversion of GTP to cGMP
B. tetramerization
C. transphosphorylation
D. involvement of two receptor types (ie, type I and type II) - correct answer ✔✔conversion of
GTP to cGMP
In the Na+/K+ pump, the energy required to move Na+ ions against its gradient is coupled to the
__________ . - correct answer ✔✔hydrolysis of ATP
Which of the following are present in the nucleus?
A. phospholipase C
B. receptor tyrosine kinases
C. G protein coupled receptors
D. all of the answers are correct - correct answer ✔✔all of the answers are correct
Genistein is a drug that inhibits tyrosine kinases. Which of the following cellular events is
susceptible to inhibition by genistein?
A. Translocation of newly synthesized phospholipids by "flippase" enzymes.
B. Binding of Grb2 to SOS protein
C. leakage of K+ through K+ channels
