NPB 100 Chapter 7 Test Bank: Comprehensive Questions and Definitions on Neurobiology

Cell-permeant signaling molecules bind to which type of receptor?

a. Channel-linked

b. Enzyme-linked

c. G-protein-coupled

d. Intracellular

e. All of the above

d. Intracellular

In a signal transduction cascade using G-proteins and cAMP, which is not a signal amplification step?

a. Activation of G-proteins by an activated receptor

b. Activation of adenylyl cyclase molecules by G-proteins

c. Creation of cAMP molecules by adenylyl cyclase

d. Phosphorylation of target proteins by protein kinase A

e. All of the above are steps in which amplification occurs

b. Activation of adenylyl cyclase molecules by G-proteins

Most enzyme-linked receptors affect the function of the target cell by

a. phosphorylating intracellular target proteins.

b. catalyzing synthesis of hormones in the cytoplasm.

c. facilitating the assembly of the cytoskeleton.

d. generating an action potential.

e. dimerizing.

a. phosphorylating intracellular target proteins.

Stimulation of metabotropic receptors cannot

a. open ion pores in the G-protein structure.

b. cause G-proteins to alter ion channels.

c. cause G-proteins to start second messenger cascades.

d. lead to widespread protein phosphorylation.

e. lead to gene transcription.

a. open ion pores in the G-protein structure.

The acetylcholine receptor at the neuromuscular junction would best be described as a(n)

a. channel-linked receptor.

b. enzyme-linked receptor.

c. G-protein-coupled receptor.

d. nuclear receptor.

e. gap junction.

a. channel-linked receptor.

The catalytic domain of a protein kinase

a. transfers a carboxyl group to the relevant amino acid of the target protein.

b. transfers a phosphate group to the relevant amino acid of the target protein.

c. transfers ATP to the relevant amino acid of the target protein.

d. binds to IP3.

e. binds to Ca2+ ions.

b. transfers a phosphate group to the relevant amino acid of the target protein.

The effector molecule at the synapse of an intercellular signal transduction process is a(n)

a. ion.

b. ion channel.

c. neurotransmitter molecule.

d. synaptic vesicle.

e. G-protein.

b. ion channel.

What is the greatest advantage of the chemical signal transduction scheme?

a. Signal amplification

b. Activation of remote targets

c. Activation of immediate targets

d. Sequential nature

e Specificity

a. Signal amplification

Which chemical signaling process is the slowest?

a. Ion channel-mediated depolarization

b. G-protein-mediated modulation of ion channels

c. Phosphorylation of effector molecules by protein kinases

d. Synthesis of proteins after CREB activation

e. All of the above types of signaling processes have similar time courses

d. Synthesis of proteins after CREB activation

Which kinase is activated by the phosphorylation of its activation loop?

a. PKA

b. PKC

c. CaMKII

d. Protein tyrosine kinase

e. MAPK

c. CaMKII

Which molecule belongs to a class of cell-associated signaling molecules?

a. Thyroxin

b. Integrin

c. Acetylcholine

d. Testosterone

e. Nitric oxide

b. Integrin

Which molecule is an effector directly downstream of an activated G-protein?

a. Phospholipase C

b. IP3

c. cAMP

d. Protein kinase C

e. Protein kinase A

a. Phospholipase C

Which neuronal mechanism increases the production of catecholamine neurotransmitters?

a. Dimerization of tyrosine kinase receptors

b. Co-activation of metabotropic and AMPA glutamate receptors

c. Phosphorylation of tyrosine hydroxylase

d. Activation of kinases that phosphorylate CREB

e. Activation of the ras cascade

c. Phosphorylation of tyrosine hydroxylase

Which of the following does not contribute to maintaining low levels of calcium in resting nerve cells?

a. Voltage-gated calcium channels

b. The plasma membrane calcium ATPase

c. The smooth endoplasmic reticulum calcium ATPase

d. The Na+ / Ca2+ calcium exchanger

e. Mitochondria

a. Voltage-gated calcium channels

Which second messenger originates from both extracellular and intracellular compartments?

a. Ca2+

b. Cyclic AMP

c. Cyclic GMP

d. IP3

e. Diacylglycerol

a. Ca2+

Which statement about protein kinases in the brain is most accurate?

a. They amplify second messenger signals.

b. Most are important regulators of neuronal signaling.

c. Each has a regulatory domain that inhibits the catalytic domain.

d. The catalytic domain of a protein kinase is always inhibited.

e. They can be activated only by second messengers.

a. They amplify second messenger signals.

Why is it crucial that Ca2+ levels are maintained at low concentrations inside the cell? What is the mechanism of action that maintains a low concentration?

Ca2+ is a second messenger, and increases in its intracellular concentration can trigger signaling cascades and other events inside the cell. Pumping of Ca2+ into the intracellular compartments and extracellular space maintains low levels of Ca2+ levels.