question_answer 28)

  The primary structure of a protein molecule has (a) two ends                      (b) one end                        (c) three ends                   (d) no ends

Answer:

                (a)The primary structure of a protien refers to a linear sequence of amino acids in polypeptide chain, held together by peptide bonds. These are two ends of a polypeptide chain, carboxyl terminus (C-terminus) and the amino terminus (N-terminus) based on the nature of the free group on each extremity.