Ion-Gated
Channels
1.
E
protein-coupled
receptor
Regulate
transport
of
ions
across
cell
membranes
external
ligand()
binding
to
a.
Receptor,
metersing
kilases
3.
are
blue
taken
operation.
receptor
(R)
activates
an
Intracellular
kinase
activity
by
auto-
GTP-binding
protein
(6),
which
regulates
phosphorylation.
an
enzyme
(Enz)
that
generates
an
Response:
·"cin
n"...
-
change
in
membrane
potential
itrase
transcription
cascade
Ligand
binding
to
specific
receptor
sites
tane
rests
on
I
Nuclear
-----
Important
Roles
->
Nervous
system:
envelope
-
)--inciear
receptor-----
protein
/
-
Protein
or
me
on
tab
in
regate
rememRNA
!EsDNA
specific
genes
-DNx
Voltage
gated
sodium
channels
Electrically
Polarized
Membrane
Nicotinic
acetylcholine
receptors
Inside
Cell
(mostly
()
charged
im
-50
Ionotropic
glutamate
receptor
outside
cell
(-70my)
Gamma
aminobutyric
acid
receptor
A
Asymmetric
transport
of
cations
(Natk
"ATPase)
(a)
The
electrogenic
Nat
K
ATPas e
establishes
the
membrane
potential.
3
Nat
out
2k
*in
flowofconic
species
across
membrane
depends
were
are
in
assist
in
the
on
concentration
gradient
+
overall
electrical
potential
voltage
-
I
voltage
-
(b)
Ions
tend
to
move
down
their
electro
chemical
gradient
membrane
Y
-
Voltage
+
Ligand
Gated
Ion
Channels:
Nerve
Signaling
e
Propagation
of
Impulse
involves
opening
of
voltage
gated
Nat
channels
Nerve
signals
within
nerves
propagate
as
electrical
Impulses
Opening
of
voltage
gated
Cat
channels
at
the
end
of
axon
(Triggers
release
of
acetylcholine)
E
Acetylcholine
opens
ligand
gated
on
channel
on
recieving
cell
