Receptors that activate second messenger pathways which can affect physically separate ion channels
Each pentameric ligand gated channel subunit has four transmembrane alpha helices (M1 through M4), with ____ assembling around the central pathway.
The ion is stabilized within the pore by energetic interactions with the _____.
amino acids forming the pore
receptors that are directly coupled to ion channels
Ions must be substantially dehydrated before they pass through the _____.
The pentameric ligand gated channels are either selective for ____, or allow permeation of both sodium and potassium.
Voltage sensing is accomplished by the ____.
The reversal of inactivation is called ________.
“removal of inactivation."
Voltage gated channels of the______ have four membrane-spanning domains, each of which contains six alpha helices (S1 through S6).
KV, NaV and CaV families
Neurotransmitter receptors are either _____ or ______.
directly coupled to ion channels; activate second messenger pathways
For both K(V) and Na(V), gating is controlled by ____.
membrane potential (Vm)
______ are structural tetramers.
Aquaporin water channels
After the _____ opens, the inactivation gate closes.
Voltage gated channels of the KV, NaV and CaV families have _____, each of which contains six alpha helices (S1 through S6).
four membrane-spanning domains
Pentameric ligand gated channels include ____, ____, _____, and _____.
GABAARs, GlyRs, nAChRs, 5-HT3Rs
What do channels select for?
1) size 2) charge 3) dehydration 4) multiple binding sites
opening the gate to allow K+ to flow out of the cell
After the activation gate opens, the inactivation gate closes, a process called ______.
Aquaporin water channels are structural ______.
When the _____ is made positive, the gate rotates to its _____ and K+ ions flow out of the cell.
inside; open position
closing of the gate to decay the current
_______ is accomplished by the S4 helices.
When the____ is made negative the gate rotates back to the closed position and _____.
inside of the cell; the current decays away
Receptors that activate second messenger pathways which can affect physically separate ion channels are called ________.
When the inside of the cell is made _____ the gate rotates back to the _____ position and the current decays away.
After the activation gate opens, the ______ closes.
The pentameric ligand gated channels are either selective for the permeation of chloride, or allow permeation of both _____ and _____.
sodium and potassium
The pentameric ligand gated channels are structurally ______.
_______ have two of its four subunits bind glutamate and the other two bind glycine.
Ions are ______ in solution by waters of hydration.