intro to core phys pharm

Question 1

Composition of the cell membrane and percentage weight

Answer 1

lipids - 42%
protein 55%
carb - 3%

Question 2

structure and function of the Na/K atpase

Answer 2

tetramer - 2 alpha 2 beta subunits
3Na : 2 K
role to maintain low intracellular Na

Question 3

different transport across membrane for different substances?

Answer 3

lipid soluble diffuse - highly selective and can cause saturation

small molecules and ions use transport proteins

large molecules endocytosis

Question 4

classification of the 3 transport proteins

Answer 4

symporter - cotransport
antiporter - exchange
uniporter - single

Question 5

What is the patch clamp test

Answer 5

study ionic currents in cell, tissue or single membrane

use pipette filled with electrolyte solution and recording electrode in it

Question 6

what determines the molecular ion channnel families ?

Answer 6

difff amino acid structure and sequence

Question 7

I = N.Po.g.(Vm-Ei) what does each symbol mean and what does it calculate

which is a constant

Answer 7

Caluculate := total current carried by population channels

I = N.Po.g.(Vm-Ei)
I = total current carried by population channels
N = no of channels
Po = open probability
g = single channel conductance
Vm = membrane potential
Ei = equilibrium potential ion i

g is a constant
a measure of the number of ions flowing through the pore per unit time.

Question 8

What was the 1st K+ channel crystal structure discovered in 1998

Answer 8

KcsA (bacterial K+ channel)
Homologous to Kir mammalian family

Grew channel protein crystals
X-ray diffraction analysis