Chapter 5 Lecture Slides Part 2 Flashcards
what do you call a ligand that cannot diffuse through the membrane?
lipophobic ligand
what is a lipophobic ligand?
a ligand that cannot diffuse through the membrane
how is a lipophobic ligand released?
from source cell vesicles by exocytosis
can a hydrophilic messenger get through a phospholipid membrane?
no!
how do hydrophilic messengers reach a target cell?
released from source cell, circulate until they contact specific surface receptors on the target cell
what is signal transduction?
changing a signal from one form to another
changing a signal from one form to another is called?
signal transduction
what are NTs?
what is their job and how are they produced?
neurotransmitters. chemical messengers produced by neurons.
how does an NT deliver its message?
NT is released by a neuron onto a target cell that is in direct contact with the neuron
what is an agonist? what does it do?
chemical that binds to a receptor. mimics the action of the natural signaling molecule.
what is an antagonist? what does it do?
chemical that binds to a receptor. competes with the normal ligand for binding, blocks/doesn’t produce a response
epinephrine (adrenaline) binds to…
a- and B-adrenergic (adrenaline-liking) receptors
what happens when epinephrine binds to a-adrenergic receptors on an intestinal blood vessel?
vessel constricts
what happens when epinephrine binds to B-adrenergic receptors on an intestinal blood vessel?
vessel dilates
what are beta-blockers? what is their purpose?
antagonists. lower blood pressure.
