Question

g What statement is TRUE about tRNA? Multiple Choice No tRNA can recognize a stop codon. Only one tRNA can recognize a stop codon. Some but not all tRNAs can recognize a stop codon. All tRNAs can recognize a stop codon, but they do so rarely. All tRNAs can recognize a stop codon, and they do so all the time.

Answer 1

No tRNA can recognize a stop codon. Instead, release factors bind to stop codons to terminate protein synthesis. This ensures that protein synthesis is concluded at the correct time.

Step-by-step explanation:

Truth About tRNA and Stop Codons

Transfer RNAs (tRNAs) are crucial for the translation of the genetic code into proteins. Each tRNA molecule has an anticodon that is complementary to a mRNA codon, enabling it to bring the correct amino acid to the growing polypeptide chain. When it comes to stop codons, which are essential signals for terminating protein synthesis, no tRNA can recognize a stop codon. Instead, release factors are responsible for recognizing stop codons and initiating the disassembly of the translation machinery, allowing for the release of the newly synthesized protein.

The statement that is true about tRNA is: No tRNA can recognize a stop codon. Stop codons include UAA, UGA, and UAG, and they do not correspond to any amino acid, nor is there a tRNA with an anticodon that recognizes them. The significance of this is that the translation process is reliably concluded at the right moment, ensuring that proteins are synthesized correctly within the cell.

Answer 2

True for tRNA: No tRNA can recognize a stop codon; when chemically modified, tRNA's anticodon will match the mRNA codon, not the modified amino acid it carries.

Step-by-step explanation:

The statement that is TRUE about tRNA is: No tRNA can recognize a stop codon. When tRNA encounters one of the three stop codons (UGA, UAA, UAG), which signal the end of protein synthesis, it does not carry an amino acid to be added to the growing peptide chain. Instead, these codons are recognized by protein release factors that trigger the termination of translation, and the release of the newly synthesized polypeptide.

With regard to the question about a chemically modified tRNA, the anticodon will match the codon in mRNA, not the modified amino acid. Even if a tRNA is chemically altered to carry a different amino acid than what is specified by its anticodon, it will still recognize and pair with the codon in the mRNA that corresponds to its anticodon sequence. This is due to the base pairing rules that govern codon-anticodon interactions during protein synthesis.