exam 2 quiz compilation Flashcards
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?
signal transduction
what is the term for a drug that can bind to a receptor and trigger signal transduction?
agonist
what receptor signaling pathway involves a cascade of phosphorylation?
receptor tyrosine kinase
what enzyme converts cAMP into AMP, thus inactivating it?
cAMP phosphodiesterase
state two types of receptors that are themselves enzymes
-receptor tyrosine kinase
-guanylyl cyclase receptors
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.
GTP (substrate) -> guanylyl cyclase -> cGMP (product)
what is the advantage of having so many steps in the signal transduction pathway of many of the receptors?
it allows for amplification of the response
the difference in charge between two locations is called the ..?
voltage
what chemicals are produced when cyclooxygenase enzymes are activated?
prostaglandins
what enzyme liberates arachidonic acid from a membrane phospholipid?
phospholipase A2
what protein does calcium bind to in order to activate a specific protein kinase?
calmodulin
what are the organs of the central nervous system?
-brain
-spinal cord
what are the two sources for the calcium that can enter the cytosol of cells?
-extracellular fluid
-smooth endoplasmic reticulum
what are the three components of a synapse?
-presynaptic terminal
-synaptic cleft
-postsynaptic density
what are the three types of synapses based on the location of the synapse on the post-synaptic cell?
-axodendritic synapse
-axosomatic synapse
-axoaxonic synapse
how does the concentration of first messenger at a receptor decrease over time?
-diffusion out of local area
-taken up by cells
-enzymes degrade the messenger
how does phosphorylation of receptors reduce the activity of the signal transduction pathway?
-receptor could lose affinity for its 1st and/or 2nd messengers
-phosphorylation can target the receptor for endocytosis
where are ryanodine receptors located?
smooth endoplasmic reticulum
draw a neuron
terms included:
-axon hillock
-dendrites
-soma
-axon
-axon collateral
-axon terminal
5 types of glial cells
- Schwann Cell
- oligodendrocyte
- astrocyte
- microglia
- ependymal cells
schwann cell
-make myelin in the peripheral nervous system
oligodendrocyte
makes myelin in the CNS
astrocyte
-regulate potassium and neurotransmitter conc. in extracellular fluid (CSF in brain)
-helps to form blood/brain barrier
microglia
immune function for the CNS
ependymal cells
line ventricles and make CSF
what two factors determine the driving force for ions
concentration gradients
electrical gradients
what equation can be used to determine the equilibrium potential for an ion?
nernst equation
if you decrease the extracellular concentration of the above cation, what will happen to its equilibrium potential?
less positive
what happens to potassiums equilibrium potential if you increase the amount of potassium in the cell?
it becomes more negative
what happens to sodiums equilibrium potential if you increase the amount of sodium outside the cell?
it becomes more positive
if an anion has a higher concentration outside the cell than inside the cell, the anions equilibrium potential will be
negative
at the RMP, which ion has the greater driving force?
sodium
assuming the only permeable ions across the plasma membrane are sodium and potassium, at the RMP
the inward flux of sodium equals the outward flux of potassium
if more potassium leaves the cell than sodium comes in, assuming those two are the only permeable ions, then the membrane potential will
become more negative
if the membrane potential becomes more negative, what happens to the driving force for sodium?
increase
if the membrane potential becomes more negative, what happens to the driving force for potassium?
decrease
if a cell does not regulate chloride concentrations, then the equilibrium potential for chloride equals the RMP in that cell
true
the concentration of potassium is the same in the CSF and the blood
false
if you increase the potassium permeability, what will happen to the membrane potential?
hyperpolarize
if you increase the intracellular concentration of sodium chloride, what will happen to the membrane potential
hyperpolarize
if you increase the intracellular concentration of potassium chloride, what will happen to the membrane potential?
hyperpolarize
changing the extracellular concentration of ________ has a bigger impact on the RMP
potassium
the movement of charge in neurons is faster than the diffusion of ions
true
when a sodium channel opens in a graded potential this cause the flux of potassium out of the cell to increase
true
at the RMP…
-the voltage gated potassium channel is closed
-the voltage gated sodium channel is closed
during the depolarization phase of the action potential
-the voltage gated potassium channel is closed
-the voltage gated sodium channel is open
during the repolarization phase of the action potential
-the voltage gated potassium channel is open
-the voltage gated sodium channel is inactivated
during the hyperpolarization phase of the action potential
-the voltage gated potassium channel is open
-the voltage gated sodium channel is closed
depolarization causes
-the activation gate of the sodium channel to open
-the inactivation gate of the sodium channel to close
-the potassium channel to open
repolarization/hyperpolarization causes
-the activation gate of the sodium channel to close
-the inactivation gate of the sodium channel to open
-the potassium channel to close
