Final answer:
Hydrophilic amino acids are found on the surface of a soluble protein, while hydrophobic amino acids are typically found in its interior. For proteins in a lipid bilayer, a mix of hydrophobic and hydrophilic amino acids would be distributed respectively with the lipid tails and the aqueous environment.
Step-by-step explanation:
The types of amino acids found on the surface of a soluble protein are generally hydrophilic. These include amino acids with polar or charged side chains such as serine (Ser), threonine (Thr), cysteine (Cys), tyrosine (Tyr), aspartic acid (Asp), asparagine (Asn), glutamic acid (Glu), glutamine (Gln), lysine (Lys), arginine (Arg), and histidine (His). On the other hand, amino acids found in the interior of a soluble protein are typically hydrophobic or nonpolar, such as valine (Val), methionine (Met), and alanine (Ala), because they are in an environment where avoiding water is optimal.
Similarly, for proteins embedded in a lipid bilayer, one would expect to find a distribution of amino acids that reflects the amphipathic nature of the protein, with hydrophobic amino acids interacting with the lipid tails and hydrophilic amino acids facing the aqueous environment or the interior channel if the protein forms one.