Grad Ch4-5 Flashcards
Signaling within neurons requires _____.
active transporters
Ion gradients are created and maintained by _____.
active transporters
Changes in membrane ion permeability are created by _____.
ion channels
Ion channels are dependent on _____.
electrochemical properties
Ions move _____ through a pump than a channel.
slower
Ions move _____ through a channel than a pump.
faster
Ion pumps require _____ to function.
energy (ATP)
Movement of an ion through a pump is a _____ process.
active
The patch clamp technique measures _____.
current flowing through a single channel
The patch clamp technique allows for experimental control of the _____.
membrane voltage
Patch clamping uses _____ currents.
microscopic
Voltage clamping uses _____ currents.
macroscopic
The probability of a Na+ channel opening increases as the membrane is _____.
depolarized
Na+ channels have a mechanism for _____, where K+ channels do not.
inactivation
Alpha-toxins slow the _____ of an AP.
inactivation
Alpha-toxins _____ the AP.
prolong
Beta-toxins shift the _____ of Na+ channels
voltage dependece
Beta-toxins cause Na+ channels to open at _____ potentials.
more negative
Na+ channels that do not inactivate are targeted by _____.
opioids
K+ channels influence the _____ and _____ of the AP.
duration
rate
K+ channels influence _____ of a neuron (undershoot).
hyperpolarization
Cl- channels control _____ and influence the _____.
excitability
resting membrane potential
The most numerous channels are _____.
K+ channels
Nearly _____ K genes are now known.
100
Ligand-gated ion channels respond to _____.
chemical signals
Ligand-gated ion channels are _____ than voltage-gated ion channels.
not as selective
Voltage-gated Na+ and Ca++ consist of _____.
4 sets of 6 regions
Voltage-gated K+ channels span the membrane _____ times (typically).
6
The bacterial K+ channel has _____ subunits.
4
The K+ channel is selective for _____.
non-hydrated K+ ions
Voltage-gated K+ channels have a _____ and a _____ to link it to the channel.
beta-subunit
T1 domain
Active transporters work _____ their concentration gradients.
against
Neuronal transporters are classified in two ways:
_____
_____
ATPase pumps
ion exchangers/cotransporters
Cotransporters work by transporting _____.
multiple ions in the same direction
The Na+ gradient is ultimately dependent on the _____.
hydrolysis of ATP by ATPase pumps
The Ca++ pump is responsible for moves _____.
Ca++ outside the cell
PMCA
Plasma Membrane Ca++ pump
SERCA
Stores Ca++ within the endoplasmic reticulum
The Na+/Ca++ exchanger moves _____.
Ca++ outside the cell
The Na+/H+ exchanger regulates _____.
intracellular pH
If extracellular K+ is removed, the Na+/K+ pump _____.
fails to function
The Na+/K+ pump contains _____ and _____.
alpha
beta subunits
The alpha subunit of the NaK pump contains amino acids that bind _____, _____, _____, _____.
ATP
Na+
K+
Ouabain
ATP is bound on the _____ side of the NaK pump
intracellular
Ouabain is bound on the _____ side of the NaK pump
extracellular
Ion flux of the Ca pump happens _____.
deep in the protein, away from the membane
Gap junctions allow for _____ flow of electric current.
passive
Gap junctions are composed of _____.
connexons
A connexon is composed of _____.
6 connexin subunits
A gap junction requires at least _____ connexons.
2
Gap junctions allow for movement of _____, _____ and _____.
current
ions
large molecules
Gap junctions allow for _____ of APs
synchronous firing
Lowei’s experiment showed that _____.
electrical information can be transferred as via a chemical signal
Neurotransmitter (3)
present in cleft
Ca++ dependent release
receptor for the molecule
2 NT categories
Small-molecule
neuropeptides
Small molecule NTs (9)
ACh Glu GABA Gly DOPA NE EPI 5HTP HA
Neuropeptide NTs (5)
ATP Substance P Endorphins Enkalphins Dynorphins
Small-molecule NTs are synthesized _____.
within the presynaptic terminal
Neuropeptides are synthesized _____.
in the soma
Small-molecules mediate _____ synaptic functions
fast
Large-molecules mediate _____ synaptic functions
slow
small-molecule NTs require _____.
low-frequency activity
large-molecule NTs require _____.
high-frequency activity
Most small NTs are removed by _____.
reuptake to the presynaptic neuron
An AP in a motor neuron results in a depolarization of the _____.
EPP
end-plate potential
MEPP
Miniature end-plate potential
Muscle contraction can be lowered by _____ or _____.
Curare
lowering extracellular Ca++
Each vesicle contains _____ molecules of ACh.
10,000
Endocytosis
recycling of the membrane of a vesicle
Synapsin
a protein keeps vesicles tethered to the reserve pool
Reserve vesicles are mobilized through _____ (by _____)
phosphorylation of synapsin
Ca++/CaMKII
SNARE proteins are regulated by _____ and _____.
ATPase NSF
SNAPs
_____ is found attached to the vesicle membrane.
Synaptobrevin
_____ and _____ are primarily found on the plasma membrane.
synataxin
SNAP-25
_____ binds Ca++ in vesicle release.
synaptotagmin
_____ and _____ cleave SNARE proteins.
botox
tetanus
_____ triggers NT release, resulting in pain and cramping.
alpha-latrotoxin
Ionotropic receptors mediate _____ postsynaptic responses.
fast
Metabotropic receptors mediate _____ postsynaptic responses.
slow
EPC
End-plate current
Channels opened by ACh are _____ to membrane voltage.
insensitive
