Lecture 6 - transport and electrophysiology

Question 1

Diffusion

Answer 1

Movement of solute molecules from high to low concentration
Move down (with) concentration gradient until equilibrium (not net movement) is reached

Question 2

Osmosis

Answer 2

The movement of water (solvent) through a semipermeable membrane from a region of low solute concentration to a region of high solute concentration

Question 3

Transport across membrane is

Answer 3

Molecules pass through phospholipid bilayer without membrane protein (non-polar)

Question 4

facilitated diffusion

Answer 4

Charged or polar solutes such as ion and glucose cross the phospholipid bilayer with the help of membrane proteins
Carrier proteins
Ion channel

Question 5

Simple diffusion

Answer 5

Molecules pass through phospholipid bilayer without membrane protein (non-polar)

Question 6

Electrical gradient

Answer 6

the difference in the net charge between two regions

Question 7

Electrochemical gradient

Answer 7

combination of electrical and concentration gradients

Question 8

Resting membrane potential

Answer 8

The electrical charge of a neuron when it is not active (-67 to -70)

Question 9

Voltage

Answer 9

Electrical gradient established by separation of charges between two locations

Question 10

Current

Answer 10

Flow of electrical charge between two points

Question 11

Flow is dependent on

Answer 11

Voltage and resistance

Question 12

Conductance

Answer 12

Relative ability of an electrical charge to migrate from one point to another

Question 13

Resistance

Answer 13

Hindrance to charge flow; inability of charge to migrate

Question 14

Insulator

Answer 14

Substance with high electrical resistance

Question 15

Conductor

Answer 15

substance with low electrical resistance

Question 16

OHM law

Answer 16

Current is the product of conductance and potential difference
No electricity of non permeable membrane is present

Question 17

OHM equation

Answer 17

I = Vg

Question 18

Equilibrium potential

Answer 18

Electrical potential difference that exactly balances on ion concentration gradient

Question 19

Large changes in membrane potential are cause by

Answer 19

Small change in ionic concentration

Question 20

Only ion at the film of the membrane

Answer 20

will be significantly chaning

Question 21

Ionic driving force

Answer 21

the difference between the real membrane potential and the equilibrium potential

Question 22

Nerst equation

Answer 22

Predict the equilibrium potential that a single ion would produce if the membrane were permeable to only that ion

Question 23

Potential is influenced by

Answer 23

concentration gradient of ion
membrane permeability to those ions

Question 24

Goldman equation

Answer 24

Calculates the resting membrane potential considering the relative permeability of different ions

Question 25

Ion channels

Answer 25

Transmembrane proteins which allow certain substances to cross membrane and pass into or out of cell

Question 26

Electrical changes across neuron plasma membrane relay on

Answer 26

ion channels resting membrane potential

Question 27

Leak channels

Answer 27

Specialized ion channels that are always open, allowing a continuously flow of ions down their concentration gradients between cytosol and ECF

Question 28

RMP is negative because

Answer 28

More K leaks out than Na leaks in

Question 29

Cell is polarized when

Answer 29

voltage difference across plasma membrane does not equal 0