Codon-anticodon pairing

Definition

Codon-anticodon pairing refers to the specific interaction between a codon in messenger RNA (mRNA) and its complementary anticodon in transfer RNA (tRNA) during the process of translation. This pairing is essential for ensuring that the correct amino acid is added to the growing polypeptide chain, thus playing a crucial role in protein synthesis.

5 Must Know Facts For Your Next Test

1. Codon-anticodon pairing follows base pairing rules, where adenine pairs with uracil (in RNA) and cytosine pairs with guanine.
2. Each tRNA molecule carries a specific amino acid that corresponds to its anticodon, ensuring that the correct amino acid is incorporated into the growing polypeptide chain.
3. The pairing occurs at the ribosome, where mRNA and tRNA come together to facilitate translation.
4. There are 64 possible codons but only 20 amino acids, which means that some amino acids are coded by more than one codon—a phenomenon known as redundancy or degeneracy.
5. Mistakes in codon-anticodon pairing can lead to incorrect amino acids being added, potentially resulting in nonfunctional proteins or diseases.

Review Questions

• How does codon-anticodon pairing ensure the accuracy of protein synthesis?
  • Codon-anticodon pairing ensures accuracy in protein synthesis by allowing tRNA molecules to bind specifically to their corresponding codons on the mRNA. Each tRNA has an anticodon that is complementary to the mRNA codon, which helps in correctly matching the right amino acid to the codon sequence. This specificity minimizes errors during translation and maintains the integrity of the protein being synthesized.
• Discuss the consequences of errors in codon-anticodon pairing during translation.
  • Errors in codon-anticodon pairing can lead to the incorporation of incorrect amino acids into the growing polypeptide chain. Such mistakes can result in nonfunctional proteins, which may disrupt cellular functions and lead to diseases. Moreover, if these errors occur frequently, they could contribute to larger-scale issues in cell metabolism or protein folding, further complicating biological processes.
• Evaluate the role of redundancy in the genetic code and its relation to codon-anticodon pairing.
  • Redundancy in the genetic code refers to the fact that multiple codons can encode the same amino acid, providing a buffer against mutations. This means that even if a mistake occurs during codon-anticodon pairing, such as an error in one specific codon, there may still be other codons available that can produce the same amino acid. This feature helps maintain protein function despite potential errors in translation and highlights an important aspect of genetic robustness in cellular biology.

Related terms

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

Anticodon: An anticodon is a sequence of three nucleotides on tRNA that is complementary to a codon on mRNA, allowing for the proper alignment of tRNA with mRNA during translation.

Translation: Translation is the process by which the information encoded in mRNA is used to assemble a specific sequence of amino acids into a polypeptide chain, ultimately forming a protein.