Question

Explain transfer RNA (tRNA) as an adaptor molecule.

Hint:

One end of tRNA reads the mRNA codon; the other end carries the amino acid. That is exactly what an adaptor does.

Answer 1

Step 1: State the problem tRNA solves.
The genetic code on messenger RNA (mRNA) is written in three letter codons of nucleotides, but the actual protein being built is made of amino acids. Nucleotides and amino acids cannot recognise each other directly, so a go-between molecule is needed.

Step 2: Describe how tRNA bridges the two.
Each tRNA molecule has an anticodon loop, a set of three bases that can base pair with a specific mRNA codon, and at its other end it carries the one specific amino acid that corresponds to that codon. So a tRNA physically links a codon on mRNA to the correct amino acid.

Step 3: Explain why this makes it an 'adaptor'.
Since tRNA reads the nucleotide language on one end (via its anticodon) and carries the protein language on the other end (its bound amino acid), it adapts, or converts, information from one chemical language into the other during translation.

Final Answer:
tRNA is called an adaptor molecule because its anticodon end reads the mRNA codon while its other end carries the matching amino acid, translating the nucleotide code into the amino acid sequence of a protein.