Transfer RNA (tRNA)

Definition

Transfer RNA (tRNA) is a type of RNA molecule that plays a critical role in protein synthesis by bringing amino acids to the ribosome during translation. Each tRNA molecule is specific to a particular amino acid and carries an anticodon that pairs with the corresponding codon on the mRNA strand. This ensures that the correct amino acid sequence is built as the ribosome reads the mRNA during protein assembly.

5 Must Know Facts For Your Next Test

1. tRNA molecules have a characteristic cloverleaf structure that allows them to effectively bind both amino acids and mRNA.
2. There are 20 different types of tRNA, each corresponding to one of the 20 standard amino acids used in protein synthesis.
3. tRNA is synthesized in the nucleus and then transported to the cytoplasm where it performs its role in translation.
4. The charging of tRNA with its specific amino acid is catalyzed by enzymes called aminoacyl-tRNA synthetases, which ensure accuracy in protein synthesis.
5. During translation, tRNA pairs its anticodon with the mRNA codon, facilitating the sequential addition of amino acids to a growing polypeptide chain.

Review Questions

• How does tRNA contribute to the accuracy of protein synthesis?
  • tRNA contributes to the accuracy of protein synthesis through its specific pairing between anticodons and codons. Each tRNA molecule carries a unique anticodon that matches a corresponding codon on the mRNA strand, ensuring that the correct amino acid is incorporated into the polypeptide chain. This precise interaction between tRNA and mRNA helps maintain fidelity in translating genetic information into functional proteins.
• Discuss the process of tRNA charging and its importance in translation.
  • tRNA charging is the process where an amino acid is covalently attached to its corresponding tRNA by enzymes known as aminoacyl-tRNA synthetases. This step is crucial because it ensures that each tRNA carries the correct amino acid for incorporation into the growing polypeptide chain during translation. If a tRNA is incorrectly charged with an amino acid, it can lead to errors in protein synthesis, potentially affecting protein function and cellular activities.
• Evaluate the role of tRNA in linking genetic information to phenotypic expression through protein synthesis.
  • tRNA serves as a vital link between genetic information encoded in mRNA and phenotypic expression through its role in protein synthesis. By accurately translating codons on mRNA into specific amino acids, tRNAs ensure that proteins are synthesized correctly according to genetic instructions. These proteins ultimately determine cellular functions and traits, illustrating how the molecular processes involving tRNA translate genetic code into observable characteristics or phenotypes.

Related terms

Amino Acid:

The building blocks of proteins, amino acids are organic compounds that combine to form proteins and are essential for various biological functions.

Ribosome: A complex molecular machine found within all living cells that serves as the site for protein synthesis, where mRNA is translated into amino acid chains.

Codon:

A sequence of three nucleotides on mRNA that corresponds to a specific amino acid or a stop signal during protein synthesis.