Midterm 1

Question 1

diffusion potential is caused by an _________ concentration difference on the two sides of the membrane

Answer 1

ion

Question 2

extracellular fluid

Answer 2

large amounts of sodium and calcium but small amounts of potassium (opposite for intracellular fluid)

Question 3

cell membrane consists of

Answer 3

lipid bilayer, protein molecules

Question 4

penetrating proteins can constitute as ____

Answer 4

transport proteins

Question 5

some proteins have watery spaces that allow for

Answer 5

free movement of water and ions and molecules

Question 6

carrier proteins

Answer 6

bind with molecules or ions to be transported

Question 7

transport through the cell membrane 2 ways

Answer 7

through the lipid bilayer or though the proteins

Question 8

simple diffusion

Answer 8

ion movement across the membrane (lipid soluble or a protein channel with varying levels of specificity)

Question 9

facilitated diffusion

Answer 9

ion movement that requires interaction with a protein to move across the membrane.

Question 10

active transport

Answer 10

ion movement across membrane that requires interaction with a protein and energy

Question 11

what properties of an ion or molecule impacts their ability to diffuse or be transported across the membrane

Answer 11

charge, size, shape, concentration gradient, membrane potential

Question 12

what circumstance utilized active transport?

Answer 12

movement against a gradient

Question 13

membrane potential

Answer 13

electrical difference when comparing the outside and inside of the cell membrane

Question 14

lipid solubility

Answer 14

how fast a substance diffuses through the membrane

Question 15

the rate of diffusion is directly proportional to its _____

Answer 15

lipid solubility

Question 16

post synaptic integration

Answer 16

spatial + temporal summation

Question 17

what maintains the two ion concentration gradients and helps produce the negative membrane potential in neurons?

Answer 17

Na+. K+ ATPase pump (but requires energy)

Question 18

what is important for ion movement in neuronal cell membranes?

Answer 18

leak channels, Na+. K+ ATPase pump, voltage gates channels, chemically gated ligand channels

Question 19

membrane potential rises high enough to block further net diffusion of sodium ions to the inside

Answer 19

j

Question 20

what creates a membrane potential?

Answer 20

a concentration difference of ions across a selectively permeable membrane

Question 21

Nernst Potential

Answer 21

the voltage required to create equilibrium for an ion with a concentration difference across a membrane

Question 22

example

Answer 22

if the electrical membrane potential inside the cell membrane is -94 mV, the electrical gradients would be strong enough to oppose the concentration gradient and prevent K+ ions from diffusing out of the cell

Question 23

neurons have ? to maintain a concentration gradient?

Answer 23

Na+. K+ ATPase pump, and K+ leak channels