Ion channels Flashcards
What does beta subunit do in receptors
Regulates function of ion channel to allow flow of ion
Hydrated ions
Ions that have a water shell around them causing a bigger diameter
Rectification
More likely to flow in one direction over the over
Inwards current is small but outwards currents is large so they will flow from inside to outside
Gating
Over flow of ions can damage the cell example calcium will cause death of cell
Once the external signal has been sensed by the ion channel it cause conformational change
Classes for gating
Voltage change can cause change
Ligand gated ion channel is opened by ligand or chemical binding to the ion channel
Mechanical channel is when there is physical force to open the channel example heroin and touch
Some channels respond to heat others respond to cold
G protein which is in the cell activates channel
Phosphorylation gated channel is when PKA and PKC catalyse for phosphorylation of protein causing change in shape
Active channels
Gates that open and close
Passive channels
Always open channels where ions are constantly flowing through
3 states of an ion channel
Closed-Ions cannot pass through membrane
Open-When activated there is opening of channel
Inactive-If there is continuous activation of channel then the channel is blocked from intracellular side this goes back to closed state when activation is gone
heterogeneous ion channels
When there are different subunits
Channelopathies
Channelopathies is mutation of subunit which can cause disease
end terminalsend terminals
Ion channel have end terminals and are important for crossing the cell membrane 6 times
Pore domain
The pore domain allows for the passing of ions formed by s5 and s6 domain
Sensor domains
Sensor domains sense changes
Gating domain
Gating domain responsible for opening and closing the gate of the channel
Tertiary structure
Different subunits come together and form in an different orientation in a compact 3d tertiary structure
