Chapter 17-Functional Organization of Endocrine System
A hormone that travels as a bound hormone can bind to any binding protein.
False
A receptor is optional, and used to maximize the response, in order for a target cell to respond to its hormone.
False
Binding proteins shorten the half-lives of the hormones to which they are bound.
False
Glandular secretions such as breast milk, sweat, or enzymes used in digestion are produced by the endocrine system.
False
Hormones must always act on tissues nearby to their point of secretion.
False
Lipid-soluble hormones, which bind to nuclear receptors, produce a faster response than water-soluble hormones that stimulate secondary messengers
False
Membrane-bound receptors interact with lipid-soluble hormones.
False
Once a hormone is bound to a binding protein, it cannot detach from it.
False
Phosphorylase activity removes a phosphate from GTP.
False
Steroid hormones are water-soluble.
False
The activity of the G protein mainly resides in the beta subunit.
False
The levels of free hormones tend to be more stable than those of bound hormones
False
The mRNA molecule moves from the cytoplasm to the nucleus and binds to a ribosome where it directs the synthesis of specific proteins.
False
A negative feedback loop is a process in which the body senses a change, and activates mechanisms to reverse that change.
True
A positive feedback loop causes a self-amplifying cycle where a physiological change leads to even greater change in the same direction.
True
Amplification is more efficient than the process of hormones binding to nuclear-bound receptors.
True
Amplification is the process of one hormone activating multiple proteins, each which activates many enzymes, which produce an enormous amount of the final product.
True
An increase in follicle-stimulating hormone causing an increase in luteinizing hormone receptors in ovary cells is an example of up-regulation.
True
Bound hormones provide a more stable supply of hormones than free hormones.
True
Epinephrine and norepinephrine are examples of water-soluble hormones.
True
Free hormones act on their target tissues immediately after being delivered from the blood.
True
Hormone amplification is faster than the process of hormones binding to nuclear-bound receptors.
True
Inactivation of the alpha subunit occurs when its own phosphorylase activity removes a phosphate from the GTP.
True
One way that the body can prevent down-regulation is through releasing brief pulses of a hormone at intervals; this ensures that the target cell will not become "saturated" with the hormone and decrease its response.
True
Steroid hormones travel in the blood attached to protein carriers.
True
The alpha subunit's separatism from the remainder of the G-protein can be repeated as long as the ligand is bound to the receptor.
True
The hypothalamus plays a role in both the nervous system and the endocrine system.
True
The tendency for one hormone to bind to only one type of receptor is called specificity.
True
The ultimate result of lipid-soluble hormones on cells is the production of proteins.
True
Water-soluble hormones are usually large.
True
Water-soluble hormones cannot usually pass through the cell membrane.
True
When concentrations of a free hormone decrease, some bound hormones will detach, creating a stable level of that hormone in the blood.
True
