1. Transcription:
* DNA contains the genetic code for making proteins.
* In the nucleus, a copy of a specific gene is made in the form of messenger RNA (mRNA).
* This mRNA molecule carries the genetic code from the DNA to the ribosomes in the cytoplasm.
2. Translation:
* Initiation: The ribosome binds to the mRNA molecule, and the first tRNA molecule carrying the corresponding amino acid (methionine) attaches to the start codon on the mRNA.
* Elongation: The ribosome moves along the mRNA, reading each codon (three-nucleotide sequence) in turn. Each codon specifies a particular amino acid.
* tRNA molecules bring the appropriate amino acids to the ribosome based on the codons.
* Peptide bond formation: The ribosome links the amino acids together to form a polypeptide chain.
* Termination: When the ribosome reaches a stop codon on the mRNA, the polypeptide chain is released.
3. Protein Folding:
* The polypeptide chain then folds into a specific three-dimensional structure, forming the functional protein. This folding is influenced by various factors, including interactions between amino acids.
In summary:
* DNA contains the genetic code.
* Transcription creates mRNA from DNA.
* Translation uses mRNA to build a polypeptide chain.
* Protein folding transforms the polypeptide into a functional protein.
This entire process is crucial for the production of proteins, which are essential for virtually all cellular processes.
