A Mutant Bacterial Cell Has a Defective Aminoacyl Synthetase That

question 78

Multiple Choice

A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal 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 options will occur; the cell will recognize the error and destroy the tRNA.

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Definitions:

Thymine

A pyrimidine nucleobase found in DNA, pairing with adenine, crucial for DNA stability and integrity.

Nucleic Acids

Biopolymers essential to all known forms of life, which carry genetic information in cells and are made up of sequences of nucleotides.

Adenine

One of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T.

Nucleic Acids

Large biomolecules essential to all known forms of life, including DNA and RNA, which store and transmit genetic information.