exam 2 quiz compilation

Question 1

what is the term for what happens in a cell between the binding of a ligand to a receptor and the final response in the cell?

Answer 1

signal transduction

Question 2

what is the term for a drug that can bind to a receptor and trigger signal transduction?

Answer 2

agonist

Question 3

what receptor signaling pathway involves a cascade of phosphorylation?

Answer 3

receptor tyrosine kinase

Question 4

what enzyme converts cAMP into AMP, thus inactivating it?

Answer 4

cAMP phosphodiesterase

Question 5

state two types of receptors that are themselves enzymes

Answer 5

-receptor tyrosine kinase
-guanylyl cyclase receptors

Question 6

what are the substrate and products of the rxn catalyzed by guanylyl cyclase? be sure to say which is the substrate and which are the products.

Answer 6

GTP (substrate) -> guanylyl cyclase -> cGMP (product)

Question 7

what is the advantage of having so many steps in the signal transduction pathway of many of the receptors?

Answer 7

it allows for amplification of the response

Question 8

the difference in charge between two locations is called the ..?

Answer 8

voltage

Question 9

what chemicals are produced when cyclooxygenase enzymes are activated?

Answer 9

prostaglandins

Question 10

what enzyme liberates arachidonic acid from a membrane phospholipid?

Answer 10

phospholipase A2

Question 11

what protein does calcium bind to in order to activate a specific protein kinase?

Answer 11

calmodulin

Question 12

what are the organs of the central nervous system?

Answer 12

-brain
-spinal cord

Question 13

what are the two sources for the calcium that can enter the cytosol of cells?

Answer 13

-extracellular fluid
-smooth endoplasmic reticulum

Question 14

what are the three components of a synapse?

Answer 14

-presynaptic terminal
-synaptic cleft
-postsynaptic density

Question 15

what are the three types of synapses based on the location of the synapse on the post-synaptic cell?

Answer 15

-axodendritic synapse
-axosomatic synapse
-axoaxonic synapse

Question 16

how does the concentration of first messenger at a receptor decrease over time?

Answer 16

-diffusion out of local area
-taken up by cells
-enzymes degrade the messenger

Question 17

how does phosphorylation of receptors reduce the activity of the signal transduction pathway?

Answer 17

-receptor could lose affinity for its 1st and/or 2nd messengers
-phosphorylation can target the receptor for endocytosis

Question 18

where are ryanodine receptors located?

Answer 18

smooth endoplasmic reticulum

Question 19

draw a neuron

Answer 19

terms included:
-axon hillock
-dendrites
-soma
-axon
-axon collateral
-axon terminal

Question 20

5 types of glial cells

Answer 20

1. Schwann Cell
2. oligodendrocyte
3. astrocyte
4. microglia
5. ependymal cells

Question 21

schwann cell

Answer 21

-make myelin in the peripheral nervous system

Question 22

oligodendrocyte

Answer 22

makes myelin in the CNS

Question 23

astrocyte

Answer 23

-regulate potassium and neurotransmitter conc. in extracellular fluid (CSF in brain)
-helps to form blood/brain barrier

Question 24

microglia

Answer 24

immune function for the CNS

Question 25

ependymal cells

Answer 25

line ventricles and make CSF

Question 26

what two factors determine the driving force for ions

Answer 26

concentration gradients electrical gradients

Question 27

what equation can be used to determine the equilibrium potential for an ion?

Answer 27

nernst equation

Question 28

if you decrease the extracellular concentration of the above cation, what will happen to its equilibrium potential?

Answer 28

less positive

Question 29

what happens to potassiums equilibrium potential if you increase the amount of potassium in the cell?

Answer 29

it becomes more negative

Question 30

what happens to sodiums equilibrium potential if you increase the amount of sodium outside the cell?

Answer 30

it becomes more positive

Question 31

if an anion has a higher concentration outside the cell than inside the cell, the anions equilibrium potential will be

Answer 31

negative

Question 32

at the RMP, which ion has the greater driving force?

Answer 32

sodium

Question 33

assuming the only permeable ions across the plasma membrane are sodium and potassium, at the RMP

Answer 33

the inward flux of sodium equals the outward flux of potassium

Question 34

if more potassium leaves the cell than sodium comes in, assuming those two are the only permeable ions, then the membrane potential will

Answer 34

become more negative

Question 35

if the membrane potential becomes more negative, what happens to the driving force for sodium?

Answer 35

increase

Question 36

if the membrane potential becomes more negative, what happens to the driving force for potassium?

Answer 36

decrease

Question 37

if a cell does not regulate chloride concentrations, then the equilibrium potential for chloride equals the RMP in that cell

Answer 37

true

Question 38

the concentration of potassium is the same in the CSF and the blood

Answer 38

false

Question 39

if you increase the potassium permeability, what will happen to the membrane potential?

Answer 39

hyperpolarize

Question 40

if you increase the intracellular concentration of sodium chloride, what will happen to the membrane potential

Answer 40

hyperpolarize

Question 41

if you increase the intracellular concentration of potassium chloride, what will happen to the membrane potential?

Answer 41

hyperpolarize

Question 42

changing the extracellular concentration of ________ has a bigger impact on the RMP

Answer 42

potassium

Question 43

the movement of charge in neurons is faster than the diffusion of ions

Answer 43

true

Question 44

when a sodium channel opens in a graded potential this cause the flux of potassium out of the cell to increase

Answer 44

true

Question 45

at the RMP...

Answer 45

-the voltage gated potassium channel is closed -the voltage gated sodium channel is closed

Question 46

during the depolarization phase of the action potential

Answer 46

-the voltage gated potassium channel is closed -the voltage gated sodium channel is open

Question 47

during the repolarization phase of the action potential

Answer 47

-the voltage gated potassium channel is open -the voltage gated sodium channel is inactivated

Question 48

during the hyperpolarization phase of the action potential

Answer 48

-the voltage gated potassium channel is open -the voltage gated sodium channel is closed

Question 49

depolarization causes

Answer 49

-the activation gate of the sodium channel to open -the inactivation gate of the sodium channel to close -the potassium channel to open

Question 50

repolarization/hyperpolarization causes

Answer 50

-the activation gate of the sodium channel to close -the inactivation gate of the sodium channel to open -the potassium channel to close