Intro to Pharmacology Flashcards
ligand definition
a chemical or compound that binds to a receptor
agonist definition
a compound that binds to an activated a receptor
antagonist definition
a compound that reduces the effect of an agonist at a receptor
partial agonist
a low efficiency agonist that is unable to elicit the maximal response from a receptor, irrespective of the concentration applied
affinity definition
a measure of the equilibrium constant of the reversible reaction between a drug (agonist or antagonist) and a receptor
efficacy definition
a measure of the magnitude of the (cellular) response produced when an agonist binds to receptor
potency definition
a measure of the concentration f a drug at which it produces an effect of a given magnitude
specificity definition
a measure of the number of receptor sites that a given drug may bind to or the range of effects it may produce
selectivity definition
the degree to which a drug binds to a given receptor site relative to other sites (related to affinity)
what is a drug
a chemical substance intentionally administered that alters body function, which is used for the prevention of treatment of a disease
what is the difference between a drug and a medicine
a medicine contains other substances
- stabilisers/ solvents
- more convenient
what do drugs target (4)
receptors (most targeted)
enzymes
carrier molecules (transporters)
ion channels
what does it mean if both agonist and antagonist can act on a receptor
there must be chemical similarities between them
there must also be chemical differences (why one activates and one blocks)
affinity lock and key analogy
affinity is how well the key fits the locke
efficacy lock and key analogy
efficacy is how well the key can turn the lock
efficacy is graded