Transfer RNA (tRNA)

Definition

Transfer RNA (tRNA) is a type of RNA molecule that plays a crucial role in translating the genetic information encoded in messenger RNA (mRNA) into proteins. Each tRNA molecule carries a specific amino acid to the ribosome, where it matches its anticodon with the corresponding codon on the mRNA strand, facilitating the addition of the correct amino acid to the growing polypeptide chain during protein synthesis.

5 Must Know Facts For Your Next Test

1. tRNA molecules have a cloverleaf structure that allows them to efficiently transport amino acids to the ribosome during translation.
2. Each tRNA is specific to one amino acid and has an anticodon that is complementary to a codon on the mRNA, ensuring accurate protein synthesis.
3. tRNA is synthesized in the nucleus and then transported to the cytoplasm, where it functions in the ribosome during translation.
4. There are at least 20 different types of tRNA, one for each of the standard amino acids used in protein synthesis.
5. The process of charging tRNA with its corresponding amino acid is facilitated by enzymes known as aminoacyl-tRNA synthetases, which ensure accuracy in protein synthesis.

Review Questions

• How does tRNA function in the process of translation, and why is its structure important?
  • tRNA functions by bringing specific amino acids to the ribosome during translation. Its cloverleaf structure allows it to bind both to an amino acid and to mRNA through its anticodon. This structural design is crucial because it enables tRNA to accurately match the correct amino acid with its corresponding codon on the mRNA, ensuring that proteins are synthesized correctly.
• Discuss the role of aminoacyl-tRNA synthetases in the function of tRNA during protein synthesis.
  • Aminoacyl-tRNA synthetases are essential enzymes that charge tRNA with their corresponding amino acids. Each synthetase is specific to one amino acid and its corresponding tRNA. This specificity ensures that when a tRNA enters the ribosome, it carries the correct amino acid for incorporation into the growing polypeptide chain. If this process is not accurate, it can lead to misfolded proteins and potential cellular dysfunction.
• Evaluate how errors in tRNA function could impact protein synthesis and cellular health.
  • Errors in tRNA function can lead to incorrect amino acids being incorporated into proteins, resulting in misfolded or nonfunctional proteins. Such misfolding can disrupt normal cellular processes, leading to diseases such as cancer or neurodegenerative disorders. Moreover, a systemic issue with tRNA function could impair overall protein synthesis, affecting cell growth and metabolism, ultimately impacting cellular health and function significantly.

Related terms

Amino Acids: The building blocks of proteins, amino acids are organic compounds that combine to form proteins and are linked together by peptide bonds.

Ribosome: A cellular structure composed of ribosomal RNA (rRNA) and proteins, ribosomes are the sites of protein synthesis where tRNA brings amino acids for assembly into polypeptides.

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