A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of a phenylalanine. The consequence of this for the cell will be that
A)none of the proteins in the cell will contain phenylalanine.
B)proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.
C)the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine-specifying anticodons.
D)the ribosome will skip a codon every time a UUU is encountered.
E)None of the above will occur; the cell will recognize the error and destroy the tRNA.

Question

Quizplus · Accepted Answer

The mutant bacterial cell will attach lysine instead of phenylalanine to tRNAs with the anticodon AAA. As a result, proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU. This is because lysine has been erroneously attached to the tRNA that recognizes UUU, and the ribosome will incorporate lysine into the growing polypeptide chain instead of phenylalanine.

A Mutant Bacterial Cell Has a Defective Aminoacyl Synthetase That