Question

If a channel is lined with amino acids that have a net positive charge, which of the following ions is/are likely to move freely through the channel?

Select one:
a. Na⁺
b. Cl⁻
c. K⁺
d. Ca⁺⁺

Answer 1

The negatively charged Cl⁻ ion is likely to move freely through a channel lined with amino acids that have a net positive charge due to electrochemical exclusion.

Step-by-step explanation:

If a channel is lined with amino acids that have a net positive charge, the ions likely to move freely through the channel are those with a net negative charge due to electrochemical exclusion. This is a phenomenon where the channel pore is charge-specific. In this case, the Cl⁻ ion would be able to move through the channel, as it has a net negative charge, and would be attracted to the positively charged amino acids lining the channel.

Other ions mentioned, including Na⁺, K⁺, and Ca⁻² are cations with positive charges and would be repelled by the positively charged amino acids, thus they are less likely to move through a channel lined with amino acids carrying a net positive charge.