Block A Lecture 3: Where do Drugs Act? Part 2 - Electric Boogaloo Flashcards
What is a transporter?
A protein which helps move molecules across a membrane in or out of the cell
(Lecture 3, Part 1, Slide 3)
What is the full name of serotonin?
5-hydroxytryptamine (5-HT)
(Lecture 3, Part 1, Slide 9)
What is serotonin?
A neurotransmitter released from the nerve cells in the brain and affects other target nerve cells
(Lecture 3, Part 1, Slide 9)
What does serotonin interact with on its target cells?
A 5-HT receptor
(Lecture 3, Part 1, Slide 9)
Serotonin is an excitatory neurotransmitter. What does this mean?
It increases brain activity
(Lecture 3, Part 1, Slide 9)
What type of drug is prozac?
An SSRI (selective serotonin re-uptake inhibitor)
(Lecture 3, Part 1, Slide 12)
What is the mechanism of action of prozac in helping treat depression?
Prozac blocks the 5HT reuptake transporter which results in more serotonin (5-HT) hanging around in the space between the two neurons, which are more likely to stimulate the 5-HT receptor on the target neuron resulting in more activity and a better mood
(Lecture 3, Part 1, Slide 12)
What does a proton pump do?
It transports H+ ions
(Lecture 3, Part 1, Slide 16)
How do proton pump inhibitors reduce the volume of stomach acid?
They inhibit H+K+ATPase irreversibly, preventing it from secreting acid
(Lecture 3, Part 1, Slide 17)
What are 3 examples of things that proton pump inhibitors can be used to treat?
Peptic ulcers
GERD (gastroesophageal reflux disease)
Gastrin producing tumour
Too much stomach acid
(Lecture 3, Part 1, Slide 18)
What are the 4 types of ion channel?
Ligand-gated
Mechanically-gated
Voltage-gated
Always open
(Lecture 3, Part 2, Slide 4)
What are ion channels?
They are pores in the membrane which allow ions to go in and out of the cell
(Lecture 3, Part 2, Slide 5)
What are ion channels made up of?
Protein subunits
(Lecture 3, Part 2, Slide 5)
What does differing protein subunit compositions in ion channels result in?
Many different channel types and variations due to subunit composition
(Lecture 3, Part 2, Slide 5)
Why do cells that are “excitable” have lots of ion channels?
As they have to respond quickly
(Lecture 3, Part 2, Slide 5)
Name 3 “excitable” cells that have lots of ion channels.
Nerve(neurons), skeletal muscle and heart (cardiac) cells
(Lecture 3, Part 2, Slide 5)
How quickly do ion channels open?
In milliseconds
(Lecture 3, Part 2, Slide 5)
What can many ion channels combine to make?
An action potential
(Lecture 3, Part 2, Slide 6)
What is an action potential?
A change in membrane potential
(Lecture 3, Part 2, Slide 6)
What mV value does membrane potential sit at?
-70
(Lecture 3, Part 2, Slide 6)
What are the first 3 steps of an action potential in neurons?
- Na+ channels open allowing Na+ (Sodium) to enter the cell - increasing membrane potential
- K+ channels open allowing K+ (Potassium) to leave the cell - this would decrease membrane potential, but more sodium goes in than potassium goes out, so membrane potential still increases
- Na+ channels become refractory, allowing no more Na+ to enter the cell
(Lecture 3, Part 2, Slide 6)
What does refractory mean?
The period of time in which a cell can’t repeat an action potential
(Lecture 3, Part 2, Slide 6)
What are the last 3 steps of an action potential in neurons (after sodium channels close)?
- K+ (Potassium) continues to leave the cell and causes membrane potential to return to the resting potential
- K+ channels close and Na+ channels rest - membrane potential goes slightly below resting level
- Extra K+ outside diffuses away, bringing membrane potential back to the resting potential level
(Lecture 3, Part 2, Slide 6)
How does action potential travel down a nerve?
It relays down the nerve until it gets to the end where transmitter release happens
(Lecture 3, Part 2, Slide 7)
