Question

Answer the following questions. For calculations, show all work. You may attach another sheet of paper (2 pt) 1. List all of the amino acids that have side chains that fit into each of the following categories: a. acidic: b. basic: c. nonpolar aromatic: d. sulfur-containing: e. hydroxyl-containing: f. achiral: (2 pt) 2. Protein Lengths. Calculate the length of a 80 amino acid-long stretch of protein if: a. It consists of pure a-helices: b. It consists of pure β strands:- c. It were fully extended: (1.5 pt) 3. The R group of the amino acid cysteine has a sulfhydryl that can be protonated or lose a proton at basic pH to form the highly reactive thiolate group. The pKa of the sulfhydryl group is 8.1 Determine the ratio of the R group that will be protonated at pH-7.1 and at pH-9.1.

Answer 1

2. List of Amino acids a. acidic: A spartic acid (Asp), Glutamic acid (Glu) b. basic: Lysin (Lys), Arginine (Arg), Histidine (His) 1S c. non-polar aromatic: Phenylalanine (Phe), Tryptophan (Trp) d. sulfur containing: Methionine (Met), Cysteine (Cys), e. hydroxyl- containing: Serine (ser), Threonine (Thr), Tyrosine (Tyr) f. achiral: Glycine (Gly)