Neuroscience-Chapter 4

Question 1

What properties do ion channels have?

Answer 1

Have to be capable of allowing ions to move across the membrane at high rates, channels have to make use of electrochemical gradients, channels have to be capable of discriminating between different types of ions, channels have to sense voltage across a membrane.

Question 2

How did the first direct evidence for the presence of voltage-sensitive, ion-selective ion channels come about?

Answer 2

Patch clamping

Question 3

What is patch clamping?

Answer 3

Technique in which a glass pipette is used to make tight contact with a tiny portion of the membrane so that the ion flow through a specific channel can be measured.

Question 4

What is the current flowing through a single channel?

Answer 4

Microscopic current

Question 5

What is the current flowing through a large number of channels?

Answer 5

Macroscopic current

Question 6

What is the primary purpose of transporters?

Answer 6

To generate transmembrane concentration gradients, which are then exploited by ion channels to generate electrical signals.