lecture 3- membrane physiology

Question 1

location of integral proteins

Answer 1

embedded in lipid bilayer

Question 2

peripheral proteins

Answer 2

polar molecules that do not penetrate the membrane

Question 3

4 building blocks of life

Answer 3

carbs, lipids, amino acids, nucleic acids

Question 4

2 types of unassisted transport

Answer 4

diffusion & conduction

Question 5

T or F: diffusion moves along gradients from high to low concentration

Answer 5

T

Question 6

T or F: conduction involves electrochemical gradients & cations are attracted to neg area

Answer 6

T

Question 7

Osmosis

Answer 7

movement of water through a membrane

Question 8

T or F: hypertonic has high concentration outside of cell

Answer 8

T

Question 9

facilitated vs active transport

Answer 9

facilitated: along gradient
active: against gradient

Question 10

4 ways conformational changes are induced

Answer 10

allosteric modulation, change in electrical field, physical deformation, phosphorylation

Question 11

membrane potential

Answer 11

separation of charge across membrane

Question 12

is the membrane negatively or positively charged inside

Answer 12

negative

Question 13

T or F: higher Na & CI outside cell & higher K+ inside during membrane potential

Answer 13

T

Question 14

resting membrane potential

Answer 14

constant in excitable & non-excitable cells at rest

Question 15

T or F: things are not moving during resting membrane potential

Answer 15

F- they are

Question 16

maintenance of resting membrane potential

Answer 16

Na/K pump uses ATP to pump 3 Na in + 2 K out

Question 17

depolarization

Answer 17

decrease in potential = less negative

Question 18

repolarization

Answer 18

returns to resting potential

Question 19

hyperpolarization

Answer 19

increase in potential = more negative

Question 20

pinocytosis

Answer 20

plasma membrane pinches off at surface & forms internal vesicle

Question 21

receptor mediated endocytosis

Answer 21

vesicle inside

Question 22

exocytosis

Answer 22

vesicle outside

Question 23

voltage gated channels respond to?

Answer 23

action potentials

Question 24

ligand channels repsond to?

Answer 24

specific signals

Question 25

graded potentials

Answer 25

local changes in membrane potential due to changes in the ECF

Question 26

what is depolarization caused by?

Answer 26

opening of Na gated channels

Question 27

Ohms law

Answer 27

voltage & distance are inversely related

Question 28

T or F: using ohms law, the further from initial site = less effect of ions

Answer 28

T

Question 29

T or F: action potentials are rapid, brief, large changes in membrane potential

Answer 29

T

Question 30

what channels close for resting potential to restore?

Answer 30

Na + K pump

Question 31

T or F: restoration of resting potential pumps 3 Na in and 2 K out

Answer 31

T

Question 32

where are action potentials initiated?

Answer 32

in the membrane where abundant voltage gated Na channels are located

Question 33

how is an action potential propagated along nerve cell?

Answer 33

dendrites receive signal and conducts action potentials along the axon to the axon terminals where chemical messengers are released

Question 34

absolute vs refractory periods

Answer 34

absolute: no re-stimulation b/c Na gates are not at rest, shorter

relative: re-stimulation can only occur through a 2nd stronger stimulus

Question 35

what is myelin made of & the function

Answer 35

lipids

increases velocity

Question 36

rode of ranvier

Answer 36

where action potential is going & sheaths propagate these actions

Question 37

excitatory response & what it leads to

Answer 37

opens non-specific cation channels to allow movement inside cells
- leads to depolarization

Question 38

inhibitory response & what it leads to

Answer 38

alters conformation of cation channels to promote movement outside cell
- leads to hyperpolarization

Question 39

temporal summation

Answer 39

several inputs from 1 axon that stimulates another response

action potentials cant do this but muscle fibers can

Question 40

spatial summation

Answer 40

same synapse type with more than 1 input

Question 41

T or F: if axons fire at same time it cancels the signal

Answer 41

T

Question 42

synaptic knob

Answer 42

production & storage of neurotransmitters

Question 43

T or F: all synapses are fast

Answer 43

F