Flashcards in 5. Ligand Gated Channels & Calcium Regulation Deck (12)
When an action potential arrives at the motor neurone terminal what channels does it open?
Voltage Gated Ca2+ channels
How does calcium entry at the motor neurone terminal initiate exocytosis?
Ca2+ binds to Synaptotagmin
Snare complex forms a fusion pore
Transmitter released through the pore
How many molecules of acetyl choline bind to nicotinic receptors on the end plate?
What does binding of Acetyl Choline on the end plate lead to?
Depolarisation leading to Voltage gated Na+ channels opening initiating and action potential on the effector
Name a competitive blocker for nicotinic Acetyl Choline receptors
How do depolarising blockers work?
Bind to nicotinic receptors but not broken down, this slow depolarisation of the membrane leads to accommodation hence inactivation of voltage gated Na+ channels adjacent to the end plate
Name an advantage of the large calcium gradient across the cell membrane.
Changes can occur quickly as it calcium diffuses rapidly across
Name a protein that transports calcium that has high affinity but low capacity.
Name a protein that transports calcium that has low affinity but high capacity.
Name four proteins that raise intracellular calcium when activated
Voltage gated calcium channels
Receptor operated calcium channels
G protein coupled receptors (Gq)
Ryanodine receptors in CICR
Why do mitochondria take up Calcium?
To protect the cell
Stimulate ATP Production
Participate in signalling in micro domains