Test 4 Review Flashcards
(40 cards)
neurotransmitters
signaling molecules that have specific receptors
cell signaling
how cells communicate with each other, using neurotransmitters
hydrophilic ligands have receptors located where?
cell surface, because these ligands are water soluble and can’t cross the lipid membrane
hydrophobic ligands have receptors located where?
intracellular, because these ligands are lipid soluble and can penetrate the lipid membrane
synapse
junction between two nerves where chemical signaling happens
4 modes of cell communication
endocrine signaling, neuroendocrine signaling, paracrine signaling, and autocrine signaling
endocrine signaling
the blood is the transporter from one cell to another
neuroendocrine signaling
neuron is taken to the target by blood
paracrine signaling
cells are very close together, and the message is transmitted by interstitial fluid
autocrine signaling
the cell message is returned to the same cell
steps that happen when the receptor is extracellular
- the ligand (1st messenger) attaches to receptor and activates G-proteins
- G-proteins are the middlemen between the receptor and adenylate cyclase enzyme
- adenylate cyclase converts ATP to cAMP
- cAMP (2nd messenger) converts inactive kinase to active kinase, catalyzing the reaction
steps taken when the receptor is intracellular
- lipid soluble ligand penetrates membrane and joins with the receptor (called ligand-receptor complex)
- the complex travels to the nucleus and attaches to the DNA
- DNA produces mRNA, which synthesizes proteins, leading to the cellular response
is the extracellular or intracellular method faster?
extracellular method is faster, and elicits a response faster as a result
3 Types of Signaling
- Agonist activates signaling-drug is the agonist and opens ion channels
- Agonist activates G protein-drug generates a second messenger and activates the signaling (extracellular receptor method)
- Agonist binds to intracellular receptor-transports to the nucleus and uses protein synthesis
which type of signaling do the majority of drugs use?
extracellular receptor method
agonist
initiates same action of neurotransmitter at receptor
full agonist and partial agonist
full-max response
partial-not complete response
antagonist
has affinity for receptor but produces no activity
competitive antagonist
competes with agonist for receptor site and blocks it
noncompetitive antagonist
binds to another part of the receptor to change the shape of the site so the neurotransmitter can’t bind to it
receptor-agonist complex
produces activity (a neurotransmitter bound to a receptor)
receptor-antagonist complex
produces no activity (blocks site or changes shape of site)
phospholipase C inhibitor (PLC)
noncompetitive antagonist that doesn’t affect the actual receptor, it just changes the reaction so that the reaction stops
intensity of drug effect characterized by 3 things:
- affinity
- intrinsic activity
- efficacy