© Macmillan Learning Resources Hint Submit Answer Determine whether the side chain of each of the amino acids is polar and neutral, nonpolar, basic, or acidic. Polar and neutral Nonpolar Answer Bank Basic H H H2N C-CH2-C-COO aspartate hydrophobic amino acid H3C-C-COO NH3 NH3 H OOC-CH2-CH2-C-COO Thr arginine Pro NH Acidic zoom

What special role does the amino acid cysteine have in the peptides vasopressin and oxytocin?

For the tripeptide GlyAlaCys a. What amino acid is located at the peptides N-terminal end? b. What amino acid is located at the peptides C-terminal end? c. How many peptide bonds are present? d. How many amide linkages are present?

22-44 How can a protein act as a buffer?

For the tripeptide SerArgIle which amino acid residues a. are hydrophilic b. are hydrophobic c. possess polar neutral R groups d. participate in two amide linkages

22-89 What kind of noncovalent interaction occurs between the following amino acids? (a) Valine and isoleucine (b) Glutamic acid and lysine (c) Tyrosine and threonine (d) Alanine and alanine

22-53 Do iron and zinc ions play role in protein structure? If so, what is the role for either or both?

For the tripeptide AlaValGly which amino acid residues, if any, a. are hydrophilic b. are hydrophobic c. possess nonpolar R groups d. participate in two amide linkages

Choose from A-F. Two of this amino acid can react with each other (anoxidation reaction) and form a covalent bond. CO- COO COO H3N-C-H H,N-C-H CH2 H2N CH 2 Н-С—он CH2 H2C CH2 CH3 CH3 Choice "A" Choice "B" Choice "C" Coo H,N-C-H H,N-C-H H3N-C-H CH2 CH2 C=CH NH CH2 C-NH | CH SH C-N H Choice "E" Choice "F" Choice "D"

2. Classify the following amino acids as nonpolar, polar basic, polar acidic, or polar neutral. (a) (b) (c) (d) H₂N-CH-COH CH-OH I CH3 || H₂N-CH-C-OH I CH₂ C=O 1 OH H₂N-CH-C-OH CH₂ T CH-CH3 CH₂ H₂N-CH-C-OH ī CH₂ OH 229