essential pharmacology Flashcards
what is a drug
a chemical agent that affects a biological system
what is meant by a receptor ?
is a binding site a drug interacts with to get into action
what does adding a small amount,large amount and maximum amount of ligand do in terms of drug- receptor interactions
small amount of ligand = small response
large amount of ligand = large response
maximum amount of ligand = maximum response
what does a higher E50 value and lower E50 indicate in terms of affinity ?
higher E50 means lower affinity
lower E50 indicates higher affinity
if affinity is high or low what direction does the graft shift to?
high affinity = left shift on x-axis
low affinity = right shift on x-axis
is E50 directly proportional or inversely proportional to the affinity between a receptor and a drug
it is inversely proportional (lower E50 means higher affinity )
how is the efficacy determined ?
how good the drug is at activating the receptor
what is meant by endogenous agents
made by the body e.g hormones , neurotransmitters
give example of exogenous
drugs
what is signal transduction ?
turning a chemical signal into an appropriate response
what is an agonist and antagonists ?
agonist ; mimics normal action of receptor
antagonist ; blocks the normal action of receptor
explain the coupling of G proteins to adenylyl cyclase
produces cAMP as 2nd messenger
cAMP regulates protein kinase A which the phoshorylates a protein and produces a cellular response
what is the biggest class of cell surface receptors?
G-protein receptors
explain the coupling of G protien to phospholipase
produces DAG and IP3 as 2nd messengers
this regulates PKC
which phosphorylates a protein and produces a response
what are properties of a full agonist ?
high affinity high efficacy
what are properties of a partial agonist
high affinity partial efficacy
what are properties of an antagonist
high affinity zero efficacy
what type of agonist is adrenaline ?
endogenous agonist
give an example of a selective agonist and what receptors it works on
sulbutamol
acts on b2 receptors causing dilation of airways.
give an example of selective antagonist
propanolol
what type of receptor does propanolol act on (selective antagonist)
b1 and b2 blocker
difference between B1 and B2 receptors
b2 = LUNGS, SMOOTH MUSCLE DIATION
B1= HEART relax
