Which of the Following Amino Acid Side Chains is Hydrophilic

Question

Which of the following amino acid side chains is hydrophilic?
A) acidic
B) basic
C) polar but neutral
D) all of these

Accepted Answer

All of these side chains are hydrophilic. Acidic side chains (such as glutamic acid and aspartic acid) are hydrophilic because they are negatively charged at physiological pH. Basic side chains (such as lysine and arginine) are hydrophilic because they are positively charged at physiological pH. Polar but neutral side chains (such as serine, threonine, and asparagine) are hydrophilic because they have partial charges that allow them to form hydrogen bonds with water.