Transcription and Translation: DNA to Protein Explained

DNA contains the genetic instructions for making proteins, stored in a double helix structure.The DNA double helix consists of two strands held together by complementary base pairs.During transcription, RNA polymerase unzips the DNA double helix, creating a transcription bubble.The resulting mRNA strand carries the genetic information that will be used to make proteins.The newly formed mRNA strand will undergo several modifications before leaving the nucleus.The newly transcribed messenger RNA undergoes several important modifications before leaving the nucleus.The pre-messenger RNA contains both coding regions called exons, shown in green, and non-coding regions called introns, shown in red.First, a protective cap is added to the five-prime end of the RNA.At the three-prime end, a string of adenine nucleotides is added, forming what's called the poly-A tail.Through a process called splicing, the introns are removed and the exons are joined together.The mature messenger RNA, now protected and properly spliced, exits the nucleus through nuclear pores.In the cytoplasm, the messenger RNA will find ribosomes, where its genetic instructions will be used to build proteins.Translation occurs at the ribosome, where messenger RNA is read to produce proteins.The ribosome reads the messenger RNA sequence in groups of three nucleotides, called codons.Transfer RNA molecules bring specific amino acids that match each codon according to the genetic code.As each amino acid arrives, it forms a peptide bond with the growing protein chain.The ribosome continues moving along the messenger RNA, adding one amino acid at a time.A peptide bond forms between each new amino acid and the growing chain.This process of chain elongation continues as the ribosome moves along the messenger RNA.The process continues until a stop codon is reached, signaling the end of protein synthesis.The completed protein chain is then released from the ribosome for folding and final modifications.