1.
Two amino acids of the standard 20 contain hydroxyl-groups. They are:
methionine and cysteine.
cysteine and serine.
cysteine and threonine.
methionine and serine.
threonine and serine.
2.
Three of the 20 amino acids that are incorporated into proteins are aromatic. They are:
tyrosine, phenylalanine, and tryptophan.
valine, leucine, and isoleucine.
tryptophan, phenylalanine, and proline.
tyrosine, phenylalanine, and proline.
arginine, lysine, and histidine.
3.
There are several amino acid side chains which are always charged at physiological pH. These are:
Glu, Asp, Lys, and His.
Gln, Asn, Glu, and Asp.
Glu, Lys, Asp, His, and Arg.
Glu, Asp, Lys, and Arg.
none of the above.
4.
Which one of the following sequences of five amino acids would most likely be located in the interior of a globular soluble protein?
Val-Ala-Val-Glu-Val
Met-Cys-Pro-His-Tyr
Met-Phe-Pro-Ile-Leu
Tyr-Phe-Glu-Asn-Leu