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Which statement describes a possible outcome for a neurotransmitter after releas

ID: 193369 • Letter: W

Question

Which statement describes a possible outcome for a neurotransmitter after release into the synaptic cleft? (Select the best answer)

A. Modulation by an enzyme, increasing its efficiency      
B. Activation of G-protein-coupled receptor on postsynaptic cell  
C. Uptake into postsynaptic cell via endocytosis      
D. Reuptake into postsynaptic terminal via transporter proteins

Most enzyme-linked receptors affect the function of the target cell by? (Select the best answer)

A. phosphorylating intracellular target proteins.
B. generating an action potential.
C. catalyzing synthesis of hormones in the cytoplasm.
D. facilitating the assembly of the cytoskeleton.

What is the greatest advantage of the chemical signal transduction scheme? (Select the best answer)

A. Activation of remote targets  
B. Specificity
C. Activation of immediate targets  
D. Signal amplification

When a GABAA ionotropic receptor is stimulated by GABA in a developing neuron, which ions flow through its channel, and what effect does this have on the postsynaptic cell? (Select the best answer)

A. Cl–, which hyperpolarizes the postsynaptic cell
B. K+, which hyperpolarizes the postsynaptic cell
C. Cl–, which depolarizes the postsynaptic cell
D. Na+, which depolarizes the postsynaptic cell

Which neuronal mechanism increases the production of catecholamine neurotransmitters? (Select the best answer)

A. Dimerization of tyrosine kinase receptors
B. Activation of the ras cascade      
C. Phosphorylation of tyrosine hydroxylase
D. Co-activation of metabotropic and AMPA glutamate receptors

Explanation / Answer

1. D. Reuptake into postsynaptic terminal via transporter proteins - Action potential causes the terminal buttons to release a small amount of neurotransmitters into the synaptic cleft and quickly takes it back.

2. A. phosphorylating intracellular target proteins.

3. D. Signal amplification - signal transduction cascades, typically amplify the message, producing multiple intracellular signals for every one receptor that is bound

4. A. Cl–, which hyperpolarizes the postsynaptic cell

5. C. Phosphorylation of tyrosine hydroxylase - Catecholamine synthesis usually is considered, to begin with tyrosine. The enzyme tyrosine hydroxylase (TH) converts the amino acid l-tyrosine into 3,4- dihydroxyphenylalanine (l-DOPA).