Question

How many pore-forming \(K^{+}\)channel subunits assemble to form a functional channel? a. One b. Two c. Four d. None of the above

Short answer

Answer: Four subunits.

Step-by-step solution

Brief background knowledge on potassium ion channels

Potassium ion (K+) channels are membrane proteins that allow the selective passage of potassium ions across the cellular membrane. These channels are important for maintaining the resting membrane potential and controlling the electrical excitability of cells.

Analyze the options

Potassium ion channels are formed by the assembly of multiple protein subunits. Let's consider each option individually: a. One subunit b. Two subunits c. Four subunits

Determine the number of subunits needed

In a functional potassium ion channel, the channel pore is formed by the assembly of four subunits. Each subunit contributes to creating the ion-selective pore. Four subunits together form a central pore in which potassium ions can pass through, and this is the minimum requirement for a properly functioning potassium ion channel.

Choose the correct answer

Based on the facts mentioned above, the correct answer is: c. Four subunits (required to form a functional potassium ion channel)