Structure of mRNA & tRNA

This lesson covers:

  1. The structure of mRNA
  2. The structure of tRNA
  3. The similarities and differences between mRNA and tRNA

mRNA

Messenger RNA (mRNA) is a type of RNA synthesised during the process of transcription.


Its role is to carry genetic information from the DNA to the ribosomes (where proteins are made).

Illustration of mRNA sequence showing codons and base pairs.

Features of mRNA:

  • Single-stranded, linear molecule.
  • Contains a base sequence complementary to a DNA sequence.
  • Contains codons, which are sets of three bases that code for an amino acid.
  • Small enough to leave the nucleus.

tRNA

Transfer RNA (tRNA) is a type of RNA used in the process of translation. 


Its role is to transport amino acids to ribosomes to build up a polypeptide chain.

Diagram showing the structure of transfer RNA (tRNA) with an amino acid binding site, anticodon, and hydrogen bonds.

Features of tRNA:

  • Single-stranded molecule folded into a clover-leaf shape.
  • Uses hydrogen bonds between complementary base pairs to hold it in shape.
  • Contains a specific sequence of three bases at one end, known as the anticodon.
  • Contains an amino acid binding site at the opposite end.

Comparing mRNA and tRNA

Table comparing mRNA and tRNA functions shapes lengths hydrogen bonds amino acid binding sites and diagrams