Lecture 2 Flashcards
(139 cards)
Another name for the specific electrical potential (voltage) created by ions in and out of a cell:
Nernst or equilibrium potential for the ion
T or F? Opening K+ channels will depolarize the cell.
F. Hyperpolarize
Will opening the Na+ channels depolarize or hyper polarize the cell?
depolarize
When is there a driving force on the ion to move it in or out of the cell?
When the cell voltage is not the same as the ion’s Nernst potential
Another name for Nernst potential:
equilibrium potential
What factors influence the MP of the cell?
driving force coupled with the ion’s channel conductance
How are the opening and closing of channels regulated?
voltage-gated, ligand-gated, or other factors
Voltage-gated cells rely on:
membrane potential
ligand-gated channels rely on:
chemicals and neurotransmitters
What creates the negative charge inside the cell?
K+ leaving (he also said the Na-K pump contributes little tot the inside negative charge)
What two forces act on ions?
charge and concentration
T or F? At equilibrium there is no flow of ions across the membrane.
F. no NET flow
When is equilibrium reached?
chem force is equal and opposite in direction to the electrical force on the ion
T or F? When a neuron is at resting potential the Na ions are at equilibrium.
F
T or F? When a neuron is at resting potential the K ions are at equilibrium.
F.
T or F? Charged molecules are not subject to a diffusive chemical driving force.
F. applies to all charged and uncharged molecules
T or F? Uncharged molecules are not subject to as electrical driving force.
T.
Another way of saying chemical gradient:
Concentration gradient
What is the diffusion of a specific ion across the PM governed by?
driving force + # of open channels
Is the Na conc high or low inside a typical nerve cell at rest?
low
In which direction do both the chemical and electrical forces go with a typical nerve cell at rest for Na?
into the cell
In which direction do the chemical and electrical forces go with a typical nerve cell at rest for Cl-?
the chemical driving force is directed inside the cell and the electrical driving force is directed outside the cell
In which direction do the chemical and electrical forces go with a typical nerve cell at rest for K?
the chemical driving force is directed outside the cell and the electrical diving force is directed inside the cell
With which molecule are the 2 driving forces complimentary, Na, K, or Cl-?
Na+