PHR 911 Comprehensive Questions With Complete Solutions

Which one of the four classes of biologically important molecules does insulin belong to? A) Carbohydrates B) Proteins C) Nucleic Acids D) Lipids E) Terpenes correct answer: B) Proteins The titration curve in Figure 1 is identified for one of the proteinogenic amino acids (used to make proteins): Which of the following is TRUE? A) The amino acid may be any of the nonpolar, aliphatic amino acids B) The first pKa represents protonation/deprotonation of the amine C) The amino acid cannot be a member of the sulfur-containing classification D) The side chain contains a carboxylate functional group E) The side chain contains an amine functional group correct answer: A)The amino acid may be any of the nonpolar, aliphatic amino acids Of the 20 standard amino acids, only _________ is not optically active. The reason is that its side chain _________. A) Ala; is a simple methyl group B) Gly; is a hydrogen atom C) Ile; is unbranched D) Lys; contains a nitrogen E) Pro; forms a covalent bond with the side chain correct answer: B) Gly; is a hydrogen atom Two amino acids of the standard 20 contain sulfur atoms. They are: A) Cys and Ser B) Cys and Thr C) Met and Cys D) Met and Ser E) Ser and Thr correct answer: C) Met and Cys 5. All of the amino acids described in class, except for Pro, contain a: (A) Primary amino group (B) Carbonyl group (C) Carboxyl side chain (D) Ester group (E) Thiol group correct answer: A) Primary amino group 6. The chirality of an amino acid results from the fact that its alpha carbon (A) Has no net charge (B) Is a carboxylic acid (C) Is bonded to four different chemical groups (D) Is in the D configuration for those incorporated into proteins (E) Is symmetric correct answer: C) is bonded to four different chemical groups 7. The amino acid Glu has an R group that makes Glu: