MT1 Flashcards
what is pharmacodynamics?
what the drug does to the body
what is pharmacokinetics?
what the body does to the drug
what is affinity?
tenacity by which a drug binds to a receptor
what is efficacy?
strength of agonist-receptor mechanism and resulting transduction mechanisms in eliciting a response
what are the intracellular and extracellular concentrations of sodium ions?
intra -> 5-15mM
extra -> 140-145mM
what are the intracellular and extracellular concentrations of potassium ions?
intra -> 140mm
extra -> 4.5mM
what are the intracellular and extracellular concentrations of calcium ions?
intra -> 100nM
extra -> 1.25mM
what are the intracellular and extracellular concentrations of hydrogen ions?
intra -> 10^-7.2M
extra -> 10^-7.4M
what are the intracellular and extracellular concentrations of chloride ions?
intra -> 5-50mM
extra -> 120mM
what are the intracellular and extracellular concentrations of HCO3- ions?
intra -> 15mM
extra -> 24mM
what is tonicity?
osmotic force exerted by a solution
what is taken as evidence of active transport?
accumulation of a substance above the level predicted at electrochemical equilibrium
why are epithelial cells considered ‘polarised’?
two membranes with different properties
allows them to perform vectorial fluxes for absorption and secretion
why is chemical transmission used at a synapse rather than direct electrical coupling?
impedance matching -> muscle cell is too large, so has too high capacitance for presynaptic current
what is the structure of an ACh receptor?
five proteins in a barrel shape
two alpha, one beta, delta, gamma
not selective - any cation
what are the three options for a synaptic vesicle after exocytosis?
kiss and stay
kiss and run
return to endosome
what is the ‘kiss and stay’ mechanism of a synaptic vesicle?
after exocytosis, vesicle remains docked at the membrane where it is refilled
what is the ‘kiss and run’ mechanism of a synaptic vesicle?
after exocytosis, pore quickly closes, then vesicle dislodges from the membrane, is reacidified and refilled
what is the ‘return’ mechanism of a synaptic vesicle?
after exocytosis, it is acidified and returned to the endosome to be recycled
what is a SNARE?
soluble NSF attachment receptor
what are the four SNARES at a neuromuscular junction?
T -> SNAP-25, syntaxin
V -> synaptobrevin, synaptotagmin
what is the function of the SNAREs?
intertwine to form complex that pulls vesicle to dock at membrane (V attaches to T)
what is the difference between V-SNAREs and T-SNAREs?
V -> on the vesicle
T -> on the membrane, ‘targets’ for V-SNAREs
which SNAREs intertwine with one another?
synaptobrevin to syntaxin
