Pairing

Definition

Pairing refers to the specific interaction between complementary nucleotides in nucleic acids, particularly in the context of the genetic code and tRNA. This interaction is crucial because it determines how information encoded in mRNA is translated into proteins. Pairing ensures that the correct amino acids are incorporated during protein synthesis by matching tRNA molecules with corresponding codons in mRNA.

5 Must Know Facts For Your Next Test

1. Pairing is essential for accurate translation, as it ensures that each tRNA brings the correct amino acid based on the codon it matches in the mRNA sequence.
2. The pairing of codons and anticodons follows strict rules, with adenine pairing with uracil (in RNA) and cytosine pairing with guanine.
3. Each tRNA molecule has a specific anticodon that pairs with one or more codons on the mRNA, reflecting the redundancy of the genetic code.
4. Incorrect pairing can lead to misincorporation of amino acids, resulting in dysfunctional proteins and potentially impacting cell function.
5. The process of pairing is facilitated by enzymes known as aminoacyl-tRNA synthetases, which attach the appropriate amino acid to its corresponding tRNA.

Review Questions

• How does pairing between codons and anticodons contribute to protein synthesis?
  • Pairing between codons in mRNA and anticodons in tRNA is fundamental for protein synthesis because it ensures that the correct amino acids are added in the proper sequence. Each tRNA carries an amino acid that corresponds to its anticodon, which pairs with a specific codon on the mRNA strand. This precise interaction dictates the order of amino acids in a growing polypeptide chain, ultimately determining the structure and function of the resulting protein.
• Discuss the consequences of incorrect pairing during translation and how it affects protein function.
  • Incorrect pairing during translation can lead to the incorporation of the wrong amino acid into a protein, which can disrupt its normal structure and function. Such errors might result from faulty tRNA molecules or mistakes in codon recognition. Proteins that are misfolded or dysfunctional due to incorrect amino acid sequences may not perform their intended roles, potentially leading to cellular malfunction or disease.
• Evaluate the role of aminoacyl-tRNA synthetases in facilitating accurate pairing during translation, considering their importance in genetic fidelity.
  • Aminoacyl-tRNA synthetases play a critical role in ensuring accurate pairing during translation by attaching the correct amino acid to its corresponding tRNA based on its anticodon. This enzyme recognizes both the tRNA molecule and its appropriate amino acid, facilitating high fidelity in protein synthesis. If these enzymes mischarge tRNAs with incorrect amino acids, it could lead to significant errors in protein assembly, ultimately affecting cellular functions and contributing to various diseases. Thus, their accuracy is vital for maintaining genetic fidelity and proper cellular activities.

Related terms

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

Anticodon:

An anticodon is a three-nucleotide sequence in tRNA that is complementary to a codon in mRNA, allowing for the correct amino acid to be added during translation.

Complementary base pairing: Complementary base pairing is the specific hydrogen bonding between adenine and thymine (or uracil) and between guanine and cytosine, which stabilizes the structure of nucleic acids.