Lecture 3 - Membrane Potentials

Question 1

What is the Nernst equation?

Answer 1

E = z (61.5) x log ([ion]outside / [ion]inside)

Z = valance ion

Question 2

What substances can cross the cell membrane without transmembrane proteins?
Which substance require transmembrane proteins?

Answer 2

Nonpolar and hydrophobic substance can cross the cell membrane without transmembrane proteins.

Polar and hydrophilic substances require transmembrane proteins to cross the cell membrane.

Question 3

At rest, the cell membrane has high permeability to __________ and low permeability to __________.

Answer 3

Potassium; sodium

Question 4

What are the mechanisms used in opening gated channels?

Answer 4

Voltage gated: changes in voltage

Ligand gated: binding of specific substance to receptors

Modality gated: mechanical deformation