fehérjekifejezés

Fehérjekifejezés refers to the process by which the genetic information encoded in DNA is used to synthesize functional protein molecules. This fundamental biological process is essential for all living organisms, as proteins perform a vast array of critical functions within cells and the body. The overall process can be broadly divided into two main stages: transcription and translation.

Transcription is the first step, where a segment of DNA, a gene, is copied into a messenger RNA (mRNA) molecule. This mRNA molecule then carries the genetic code from the DNA, which is located in the nucleus of eukaryotic cells, out into the cytoplasm.

Translation is the second stage, which occurs in the cytoplasm on structures called ribosomes. Here, the mRNA sequence is read in three-nucleotide units called codons. Each codon specifies a particular amino acid. Transfer RNA (tRNA) molecules bring the corresponding amino acids to the ribosome, where they are linked together in the order dictated by the mRNA sequence, forming a polypeptide chain. This polypeptide chain then folds into a specific three-dimensional structure, becoming a functional protein. The sequence of amino acids determines the protein's structure and, consequently, its function. Variations in this process can lead to different protein products and are fundamental to cellular diversity and organismal development.