An amino acid analyzer is an instrument used to determine a. the sequence of amino acids in a polypeptide chain b. the presence of modified amino acids in a protein c. the identity of N-terminal and C-terminal amino acids in a protein d. the identities and relative amounts of amino acids in a protein

d. the identities and relative amounts of amino acids in a protein

Explanation:

An amino acid analyzer is an automated machine that is used to determine the identities and quantities of amino acids in a given protein, peptide, and cellular samples. It makes use of the ion-exchange chromatography principle to determine the presence of amino acids. When the chromatogram is obtained, the relative amounts are then determined by the analyzer.

Since proteins are made of sequences of amino acids, the identities of proteins can also be obtained through this method. Ninhydrin, in the chromatographic column, reacts with the present amino acids under an ultra violet detector and is then observed at a wavelength of about 440 - 570nm.