Fehérjekódolás

Fehérjekódolás, also known as protein coding, refers to the process by which the genetic information encoded within DNA or RNA is translated into a sequence of amino acids, which then fold into functional proteins. This fundamental biological process is central to gene expression and the synthesis of all proteins within a living organism.

The genetic code itself is a set of rules that dictates how nucleotide sequences are translated into amino acid sequences. This code is nearly universal across all life forms. It consists of codons, which are sequences of three nucleotides that specify a particular amino acid or a stop signal. For example, the codon AUG codes for the amino acid methionine and also serves as the start codon for most protein synthesis. Conversely, codons like UAA, UAG, and UGA signal the termination of protein synthesis.

The process of protein coding involves two main stages: transcription and translation. Transcription is the synthesis of an RNA molecule from a DNA template. This RNA molecule, called messenger RNA (mRNA), carries the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm. Translation is the process where ribosomes read the mRNA sequence and, with the help of transfer RNA (tRNA) molecules that carry specific amino acids, assemble these amino acids into a polypeptide chain. This polypeptide chain then undergoes further modifications and folding to become a functional protein. Variations or errors in the DNA sequence, known as mutations, can lead to changes in the mRNA sequence, potentially altering the amino acid sequence of the resulting protein and affecting its function.