MT1 PP Open Questions Flashcards
The open probability of an ion channel can range from __ to __
0 to 1
(or 0 to 100%)
Ion channels are protein pores that span the _____
plasma / bilipid membrane
The protein segment responsible for K channel selectivity is called the ____
P loop
The selectivity filter of a K+ channel is located close to the ____ side
extracellular
The central cavity of an ion channel communicates with
which solution through the gate?
Intracellular solution
During N-type inactivation, the N terminal peptide segment of a voltage gated K channel plugs its pore from the _______ side
intracellular
ATP-sensitive K+ channels are involved in regulation of which hormone?
Insulin secretion from pancreatic beta cells
Type II diabetes mellitus can be treated by sulphonylureas. What effect do they have on the ATP-sensitive K+ channels:
Sulfonylureas (tolbutamide) inhibit the ATP-sensitive K+ channels by binding to the SUR1 subunit in pancreatic beta cells. Inhibiting the channel leads to easier depolarization and insulin release from the beta-cells – which can lower blood sugar level.
At high ionic concentrations the ion channel throughput rate becomes:
saturated
The gate of a K+ channel is located close to the ____ side
intracellular
Which transmitter is released from the motoneurons stimulating muscle contraction?
Through which receptor is it mediated?
What second messenger is essential for the above process?
acetycholine
nicotinic acetycholine receptor
Ca2+ is second messenger
List the names of the intermediates that are produced in the consecutive steps of noradrenaline synthesis
Tyrosine -> DOPA -> dopamine -> noradrenaline
![](https://s3.amazonaws.com/brainscape-prod/system/cm/181/669/661/a_image_thumb.jpg?1456423657)
How does dopamine influence (decrease, increase, or no effect) the kidney:
- effect on Na+/K+ ATP-ase
- rate of Na+ reabsorption
decrease for both
Name the metabolite that is formed in the brain in the metabolism of noradrenaline and can be detected in the urine
MHPG
3-Methoxy-4-hydroxyphenylglycol
Name a hormone that stimulates the activity of Na+,K+ ATPase
Norepinephrine
Also Aldosterone