Question

8. A membrane spanning protein that is a channel for potassium ion transport is made up of six copies of a single polypeptide. Potassium ions are transported across the membrane using the channel. What type of amino acids do you expect to find on the exterior of the channel next to the tails of the membrane lipids?

a. Negatively charged

b. Positively charged

c. Nonpolar

d. Polar

Answer 1

Option c is the correct answer.

Since in the question we are asked about what type of amino acids do we expect to find on the exterior of the channel next to the tails the membrane lipids.

We know that tails of the membrane lipids are Hydrophobic that is they repelled and are not soluble in water so are the non polar amino acids which are repelled and they are not soluble in water.

So, we can expect to find non-polar amino acids next to tails of membrane lipids because non-polar amino acids are hydrophobic and insoluble in water and also the R- group contains only hydrocarbons mostly, cysteine and methionine have a sulphur group but yet, this does not add to any polar property of these amino acids.