Test #3 CORRECT ANSWERS IN RED Question 1 True or False: The amino acids cysteine and serine both contain sulfur atoms. True False Question 2 True or False: The following secondary structure shown below is an example of an Antiparallel beta sheet. True False Question 3 True or False. The side chain of leucine is bonded to the backbone nitrogen atom. True False Question 4 True or False: The name of the molecule that binds to an enzyme is called the apoenzyme. True False Question 5 True or False: An inhibitor that binds at the active site is an uncompetitive inhibitor. True False Question 6 Which amino acids both have an R group (side chain) with an -OH functional group? Leu and Ile Ala and Ser Ser and Thr You Answered Asp and Asn Ser and Cys Question 7 The formation of a peptide bond between two amino acids is an example of a(n) reaction. Cleavage Condensation Group transfer You Answered Isomerization Double-bond breaking Question 8 The peptide Ala-Glu-Gly-Ala-Leu has . A disulfide bond Five peptide bonds Four peptide bonds A proline residue No C-terminal Question 9 Formally, when there are 100 or more amino acids are covalently linked together that is called a . Polypeptide Oligopeptide Peptide Protein Polyprotein Question 10 What unit is used by biochemists to indicate the mass of a protein? kDa kBa Mol/g g/mol kg Question 11 All of the 20 standard amino acids contain an R-group that is attached to the: A. Carboxyl group B. Amino group C. Alpha carbon D. Beta carbon E. It depends on the amino acid A. B. C. D. E. Question 12 Which of the following correctly matches the amino acid with its one letter abbreviation? Glutamic acid, E Isoleucine, S Lysine, L Phenylalanine, P Arginine, A Question 13 By convention, polypeptides are read in which order? N to C-terminus C to N-terminus 5’ to 3’ 3’ to 5’ Smallest to largest amino acid by weight Question 14 In one turn of a helix, there approximate amino acids. 2.3 3.6 4.2 5.4 None of the above Question 15 In an alpha helix, the R groups on the amino acid residues