General Info
Specificity of target cell receptors means they:
only respond to certain (specific) hormones
If levels of a hormone are too low, what action could a target cell take?
Up-regulation of receptors
What binds with and activates the G-protein linked receptor?
the hormone
Which hormone categories are hydrophilic?
Peptide hormones and most amines (not thyroid hormone)
Hormones are a type of:
extracellular chemical messenger
When one hormone up-regulates receptors for a second hormone or when both hormones are required.
Permissiveness
What is produced by adenylate cyclase?
cAMP
Hydrophilic hormones typically have receptors located where?
On the plasma membrane of the target cell
These are locally acting chemical messengers.
Paracrine secretions
What does activated G-protein activate?
Adenylate cyclase
What does cAMP activate?
protein kinase A
Which hormone category includes hormones that are made from cholesterol?
Steroid hormones
These glands release their product into ducts AND into the blood.
Mixed glands (endocrine and exocrine)
Too much hormone or _______________, can cause endocrine disorders.
hypersecretion
G-protein linked receptor systems are a type of __________________.
second messenger system
Hormone levels may be controlled by:
another hormone, levels of nutrients in the blood, or the nervous system
Which category of hormone would have hormones that tend to have a longer half-life?
Steroid: Hydrophobic and therefore use transport proteins
If all of the receptors for a hormone are full then the target cell has reached ________________.
saturation
What does activated G-protein bind?
GTP
If a hormone acts antagonistically to another hormone, what might it do to the target cells for that hormone?
down regulate receptors for the hormone