An operon encodes enzymes for making an essential amino acid and is regulated like the trp operon. which of the statements is true? a. the amino acid inactivates the repressor. b. the amino acid acts as a corepressor. c. inducible enzymes are produced. d. the repressor is active in the absence of the amino acid.

Protein and polypeptide sequences can be determined by first partially hydrolyzing the protein or polypeptide followed by amino acid sequencing of the fragment pieces using the chemical degradation process known as edman degradation. determine the sequence of the initial (18-amino acid) polypeptide that produces the following five partial sequences after hydrolysis and edman degradation.