Which feature distinguishes tRNA from mRNA?

Which feature distinguishes tRNA from mRNA?

• A. Cloverleaf shape
• B. Contains introns
• C. Longer than mRNA
• D. Encodes protein

Answer: (A)

The defining feature is the cloverleaf secondary structure that tRNA adopts due to internal base pairing. This folding creates distinct arms—the acceptor stem, D arm, anticodon loop, and TΨC arm—that position the anticodon to read mRNA codons and hold the amino acid on the 3' end. mRNA, on the other hand, is a linear molecule that serves as a template for protein synthesis and does not have this universal, fixed cloverleaf structure. While some tRNA genes may contain introns and mRNA can be longer or subject to splicing, these are not universal distinguishing traits; the cloverleaf shape is the hallmark that sets tRNA apart.

The defining feature is the cloverleaf secondary structure that tRNA adopts due to internal base pairing. This folding creates distinct arms—the acceptor stem, D arm, anticodon loop, and TΨC arm—that position the anticodon to read mRNA codons and hold the amino acid on the 3' end. mRNA, on the other hand, is a linear molecule that serves as a template for protein synthesis and does not have this universal, fixed cloverleaf structure. While some tRNA genes may contain introns and mRNA can be longer or subject to splicing, these are not universal distinguishing traits; the cloverleaf shape is the hallmark that sets tRNA apart.