Here's how it works:
1. DNA contains the genetic code: The instructions for building a polypeptide chain are encoded within the DNA molecule.
2. Transcription: The DNA sequence is transcribed into mRNA. This means a copy of the gene is made in the form of mRNA.
3. Translation: The mRNA molecule travels to the ribosome, which is the site of protein synthesis. Here, the mRNA sequence is translated into a polypeptide chain. Each three-nucleotide sequence (codon) on the mRNA specifies a particular amino acid.
4. Polypeptide chain formation: The ribosome reads the mRNA codons and adds the corresponding amino acids to the growing polypeptide chain.
5. Folding and processing: After the polypeptide chain is complete, it folds into a specific three-dimensional structure and may undergo further processing to become a functional protein.
Therefore, mRNA acts as the intermediary between DNA and the protein-building machinery of the cell. It carries the genetic code from DNA to the ribosome, where the polypeptide chain is synthesized.
