+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
What are peptide hormones?
|
lipophobic hormones that contain copies of the hormone and a signal sequence to direct it to the RER
unable to enter target cell |
|
What does it mean if a hormone is lipophobic?
|
It dissolves easily in extracellular fluidunable to enter target cells
|
|
What are steroid hormones derived from?
|
cholesterol
|
|
Where are steroid hormones produced?
|
gonads, placenta, cortex of adrenal gland
|
|
Are steroid hormones soluble in plasma?
|
No, they are lipopphyllic.most steroid hormones found in the blood are bound to a carrier protein.
|
|
What do gonads produce?
|
sex hormones
|
|
What is the mechanism of signal transduction for peptide hormones?
|
The bind to the cell surface receptors because they cannot enter the cell otherwise.
GPCR (G-protein coupled receptor)tyrosine kinase coupled receptorscAMP second messenger systems |
|
Why is cell response to peptide hormones rapid?
|
Because second messenger systems modify existing proteins.
|
|
What is a preprohormone?
|
MRNA on the ribosome binds amino acids into a peptide chain
inactivepeptide hormone synthesis |
|
What is a prohormone?
|
Enzymes in the ER chop off the signal sequence creating an inactive prohormone.
inactivebecomes activated during protranslational modification |
|
What is protranslational modification?
|
When prolytic enzymes chop the prohormone into active hormone and other fragments
|
|
What is an echtohormone?
|
A hormone secreted by a cell to the external environmentex: pheremones
|
|
What makes a chemical a hormone?
|
It is secreted by a cell or group of cells into the blood or external environment
exerts it's effect at very low blood concentrations |
|
What is a catecholamine?
|
Fight or flight hormonesreleased by the adrenal glands in response to stresspart of the sympathetic nervous systemusually stimulant drugs
|
|
What is acetylcholinesterase?
|
degrades acetylcholineterminates synaptic transmission
|
