How is the genetic code read during translation?

The genetic code is read during translation in sets of three nucleotides called codons.

During the process of translation, the genetic code is read by the ribosome, a cellular machinery that synthesises proteins. This process begins with the initiation phase, where the ribosome attaches to the mRNA at the start codon (AUG). The genetic code is read in sets of three nucleotides, known as codons. Each codon corresponds to a specific amino acid or a stop signal.

The ribosome moves along the mRNA, reading the codons in a 5' to 3' direction. As each codon is read, a molecule of transfer RNA (tRNA) that carries the corresponding amino acid binds to the codon. The tRNA has an anticodon region that is complementary to the mRNA codon, ensuring the correct amino acid is incorporated into the growing polypeptide chain.

This process continues during the elongation phase of translation, with the ribosome moving along the mRNA, reading the codons and facilitating the binding of tRNA molecules. The amino acids brought by the tRNA molecules are joined together by peptide bonds to form a polypeptide chain. This chain will eventually fold into a functional protein.

The translation process ends during the termination phase when the ribosome encounters a stop codon (UAA, UAG, or UGA). These codons do not code for any amino acid, and thus signal the end of protein synthesis. At this point, the polypeptide chain is released from the ribosome and the translation machinery disassembles.

In summary, the genetic code is read during translation in sets of three nucleotides, or codons. The ribosome reads these codons and facilitates the binding of tRNA molecules carrying the corresponding amino acids. This process continues until a stop codon is encountered, signalling the end of protein synthesis.