Transfer RNA (tRNA)

Definition

Transfer RNA (tRNA) is a type of RNA molecule that plays a critical role in protein synthesis by transporting amino acids to the ribosome, where proteins are assembled. Each tRNA molecule is specific to one amino acid and has an anticodon that pairs with the corresponding codon on the mRNA strand during translation, ensuring that the correct amino acids are incorporated into the growing polypeptide chain.

5 Must Know Facts For Your Next Test

1. tRNA molecules have a cloverleaf structure that allows them to effectively recognize and bind to specific amino acids and codons on mRNA.
2. Each tRNA is charged with an amino acid by an enzyme called aminoacyl-tRNA synthetase, which ensures that the correct amino acid is attached to the corresponding tRNA.
3. The anticodon of tRNA pairs with a complementary codon on the mRNA strand during translation, ensuring accurate translation of genetic information into protein.
4. There are approximately 20 different tRNAs, each corresponding to one of the 20 standard amino acids used in protein synthesis.
5. tRNA not only helps in assembling proteins but also plays a role in regulating gene expression and cellular metabolism.

Review Questions

• How does tRNA contribute to the accuracy of protein synthesis during translation?
  • tRNA contributes to the accuracy of protein synthesis by ensuring that each amino acid is added to the growing polypeptide chain in accordance with the sequence encoded by the mRNA. Each tRNA molecule has a specific anticodon that pairs with a corresponding codon on the mRNA strand. This complementary base pairing between the tRNA anticodon and mRNA codon helps prevent errors in protein assembly, allowing for precise translation of genetic information.
• Discuss the role of aminoacyl-tRNA synthetase in relation to tRNA and its importance in protein synthesis.
  • Aminoacyl-tRNA synthetase is an enzyme responsible for attaching the correct amino acid to its corresponding tRNA molecule. This charging process is crucial for protein synthesis, as it ensures that tRNAs carry the proper amino acids needed for translation. If an incorrect amino acid is attached, it could lead to mutations or dysfunctional proteins. Therefore, aminoacyl-tRNA synthetase plays a vital role in maintaining fidelity during the process of translating genetic information into functional proteins.
• Evaluate how the structure of tRNA affects its function in protein synthesis and what implications this has for cellular processes.
  • The cloverleaf structure of tRNA allows it to effectively interact with both amino acids and mRNA codons, facilitating its essential role in protein synthesis. This unique shape provides distinct sites for amino acid binding and codon recognition, ensuring accurate translation. If there were any alterations in tRNA structure, it could lead to misincorporation of amino acids into proteins, potentially disrupting cellular functions and leading to diseases. Understanding this relationship between structure and function highlights how crucial tRNA is for maintaining proper cellular processes and overall organismal health.

Related terms

Ribosome: A cellular structure made of ribosomal RNA and proteins that facilitates the assembly of amino acids into protein chains during translation.

Amino Acid: The building blocks of proteins, which are linked together in specific sequences to form polypeptides and ultimately functional proteins.

Messenger RNA (mRNA): A type of RNA that carries the genetic information from DNA to the ribosome, serving as a template for protein synthesis during translation.