Endocrine System (Mylab and Mastering) Questions With
Complete Solutions
What do steroids and amino acid-based hormones have in
common?
Steroids and amino acid-based hormones are secreted by
endocrine glands.
(Although most hormones secreted by endocrine glands are
amino acids, gonadal and adrenocortical hormones, both
steroids, are also produced by endocrine glands.)
What is the role of the protein kinases in a cell?
When activated, they phosphorylate other proteins, including
other enzymes.
(Protein kinases are enzymes that, when activated by a second
messenger, phosphorylate (give a phosphate group to) other
proteins. This may activate or inhibit various cellular processes.)
Which of the following is a characteristic of thyroid
hormone?
A. Thyroid hormone activates the PIP2-calcium signaling
mechanism.
B. Thyroid hormone initiates the second-messenger cAMP.
C. Thyroid hormone is lipid soluble.
,D. Thyroid hormone is a type of steroid hormone.
Thyroid hormone is lipid soluble.
(Although thyroid hormone is composed of amino acids, it is
lipid soluble and capable of crossing the plasma membrane.)
How do steroid hormones and thyroid hormone affect
change in their target cells?
The hormone passes through the cell membrane and activates
intracellular receptors that enter the nucleus to activate genes.
(Steroid hormones may cross the plasma membrane and bind to
intracellular receptors. This receptor-hormone complex may
then directly bind to DNA in the nucleus.)
Low blood glucose concentration and high blood potassium
concentration are examples of __________ stimuli for an
endocrine gland.
humoral
(Some endocrine glands secrete their hormones in direct
response to changing blood levels of certain critical ions (such
as K+) and nutrients (such as glucose). These stimuli are called
humoral stimuli (from the Latin term humor, which refers to
bodily fluids).)
,Hormones that bind to plasma proteins ________.
are usually synthesized from cholesterol
True or False: Water-soluble hormones are inactivated and
removed from the blood by the liver.
False
(Water-soluble hormones are rapidly removed from the blood by
the kidneys.)
What determines whether a particular cell is able to respond
to a hormone?
the presence of a specific hormone receptor
(Any cell that has a specific receptor for a specific hormone is a
target cell of that hormone. Binding of the hormone to the
receptor triggers a response from the target cell.)
Which of the following occurs in situations where different
hormones produce the same effects at the same target cell
and their combined effects are amplified?
A. summation
B. synergism
C. permissiveness
D. antagonism
synergism
(Synergism occurs when more than one hormone produces the
, same effects at the target cell and their combined effects are
amplified. For example, let's say both hormone "A" and
hormone "B" cause the liver to release glucose into the blood.
When they act together, the amount of glucose released might be
150% of what is released if each hormone acts independently.)
Which of the following is characteristic of water-soluble
hormones?
A. binding to intracellular receptors at their target cells
B. exhibiting a long half-life in the blood
C. acting through second messengers at their target cells
D. circulating in the blood bound to protein carriers
acting through second messengers at their target cells
(Water-soluble hormones exert their signaling effects through
intracellular second messengers generated when the hormone
binds to a receptor in the plasma membrane.)
In circumstances where the body requires prolonged or
increased levels of a hormone, the DNA of target cells will
specify the synthesis of more receptors on the surface of the
cells of the target organ. This is known as ________.
up-regulation
Dave has discovered a new lipid-soluble hormone. Which of
the following is true regarding this hormone?
A. will likely act through a second-messenger system
B. can be stored in secretory vesicles