What type of hormone-receptor action allows insulin to move glucose into cells?
A. activation of cGMP
B. activation of adenylate cyclase
C. direct alteration of intracellular enzymes
D. phosphorylation of intracellular proteins
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Question 2) Hormones act on specific tissues called _______ tissues.
Fill in the blank(s) with the appropriate word(s).
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Question 3) Which intracellular mediator is directly activated by the binding of a water-soluble hormone to a membrane receptor?
A. cGMP
B. cAMP
C. calmodulin
D. phospholipase C
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Question 4) Consider the following events in the nuclear receptor model:
(1) Hormone receptor complex binds to DNA.
(2) Messenger RNA directs synthesis of specific proteins.
(3) Hormone binds to receptors in the nucleus (sometimes in the cytoplasm)
(4) Messenger RNA synthesis is activated.
(5) Synthesized proteins produce the response of the cell.
Which of these events occurs in the nucleus?
A. 1, 3, 5
B. 1, 3, 4
C. 1, 2, 3
D. 3, 4, 5
E. All events occur in the nucleus.
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Question 5) Which of the following occurs when a hormone binds to a nuclear receptor?
A. activation of cyclic AMP
B. activation of mRNA synthesis
C. increased lipid synthesis by ribosomes
D. opens membrane channels
E. alters membrane permeability
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Question 6) Arrange the following events in proper sequence:
(1) The activating hormone interacts with a membrane-bound receptor.
(2) Cyclic AMP causes the cell to carry out a function characteristic for that specific hormone.
(3) Adenylyl cyclase catalyzes the transformation of ATP to cyclic AMP.
(4) Adenylyl cyclase is activated.
A. 1, 2, 3, 4
B. 1, 4, 3, 2
C. 3, 4, 2, 1
D. 1, 3, 2, 4
E. 1, 3, 4, 2
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Question 7) Phosphodiesterase functions
A. as a membrane-bound receptor molecule.
B. to inactivate cyclic AMP.
C. to attach phosphate groups to enzymes.
D. to combine GTP with cyclic AMP.
E. activates cGMP.
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Question 8) When a hormone binds to a membranebound receptor and activates G proteins,
A. ion channels could be opened.
B. IP3 may be activated.
C. cyclic AMP production may be increased.
D. DAG may be activated.
E. All of the choices may occur from activated G proteins.
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Question 9) When a few intracellular mediator molecules activate several enzymes, and each of these activated enzymes activate still other enzymes, the hormone has initiated
A. a cascade effect.
B. a double loop effect.
C. a protein kinase effect.
D. a cyclic effect.
E. a negative feedback cycle.
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Question 10) When a hormone binds to a membranebound receptor,
A. membrane channels are destroyed.
B. cyclic GMP might be produced to act as an intracellular mediator.
C. the nucleus is phosphorylated to prevent G-protein activation.
D. messenger RNA is formed.
E. cellular DNA is altered.
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