onsider the amino acids glycine, proline and lysine. a. How many tripeptides can be formed from these three amino acids if each is used only once in the structure? b. Using three-letter abbreviations for the amino acids, give the sequence of each of the possible tripeptides. c. Draw the structure of the dipeptide that has proline at its N-terminal amino acid and glycine as its C-terminal amino acid. Circle each peptide bond.

acids Identify which of the following are a-amino acids. CH₁ H₂N-C-COOH a. CH₁ H b. H₂N-C-CH₂-COOH 1 CH, H c. H₂N-CH₂-C-COOH H 1 d. H₂N-C-COOH CH₂CH,

1. Determine whether each of the following statements describes the primary, secondary, tertiary, or quaternary stucture of a protein. а. Peptide bonds join amino acids in a polypeptide chain. b. Two polypeptide chains are held together by hydrogen bonds. С. Hydrogen bonds form between adjacent segments of the backbone of the same protein to form a "folded fan" structure. 2. List the type of denaturing agent described by the following treatments: a. disrupting the disulfide bonds in hair to straighten it b. baking the proteins in dough to make bread

The building blocks of all proteins are a. pleated sheetsb. alpha amino acidsc. alpha helicesd. tertiary structurese. none of these