In gene expression, mRNA, tRNA, and rRNA work together to produce proteins from genetic information stored in DNA. Each plays a specific and essential role in the process of translation:
- mRNA (Messenger RNA)
- Role: Carries the genetic code from DNA in the nucleus to the ribosomes in the cytoplasm.
- Function: Acts as a “blueprint” for building a specific protein.
- It contains codons, which are three-base sequences that specify particular amino acids.
- Example: If DNA has a sequence TAC, the mRNA codon will be AUG, which codes for the amino acid methionine.
- tRNA (Transfer RNA)
- Role: Brings amino acids to the ribosome during protein synthesis.
- Function: Acts as an “adapter” that matches the mRNA codon with the correct amino acid.
- Each tRNA has:
- An anticodon that pairs with the mRNA codon.
- An attached amino acid that will be added to the growing protein chain.
- Example: If the mRNA codon is AUG, the tRNA anticodon will be UAC, carrying methionine.
- rRNA (Ribosomal RNA)
- Role: Forms the main structure of ribosomes, along with ribosomal proteins.
- Function: Provides a site for translation and catalyzes the formation of peptide bonds between amino acids.
- rRNA ensures the proper alignment of mRNA and tRNAs during protein synthesis.
In summary:
- mRNA = messenger carrying genetic information
- tRNA = transporter bringing amino acids
- rRNA = builder forming the ribosome and linking amino acids together
Together, these RNAs coordinate to translate the genetic code into functional proteins — the final step in gene expression.