1. Transcription
* DNA unwinds: The DNA double helix unwinds, exposing the gene containing the code for the desired protein.
* Transcription: An enzyme called RNA polymerase reads the DNA sequence and creates a complementary messenger RNA (mRNA) molecule. The mRNA molecule carries the genetic code from the DNA in the nucleus to the ribosome in the cytoplasm.
* mRNA processing: The mRNA molecule undergoes modifications, including the addition of a 5' cap and a poly-A tail. These modifications protect the mRNA from degradation and help it bind to the ribosome.
2. Translation
* Ribosome binding: The mRNA molecule attaches to a ribosome.
* tRNA binding: Transfer RNA (tRNA) molecules, each carrying a specific amino acid, bind to the mRNA molecule according to the genetic code.
* Peptide bond formation: The ribosome moves along the mRNA, reading the codons (groups of three nucleotides). As it does, the amino acids carried by the tRNAs are linked together by peptide bonds, forming a polypeptide chain.
* Chain elongation: This process continues until the ribosome reaches a stop codon on the mRNA.
* Protein folding: Once the polypeptide chain is complete, it folds into a specific three-dimensional shape. This shape is essential for the protein's function.
* Post-translational modifications: The protein may undergo further modifications, such as phosphorylation, glycosylation, or cleavage, which can affect its activity and stability.
Summary:
1. DNA provides the genetic code.
2. Transcription creates an mRNA copy of the code.
3. mRNA travels to the ribosome.
4. Translation reads the mRNA code and assembles amino acids into a polypeptide chain.
5. The polypeptide chain folds into a functional protein.
Let me know if you'd like a more detailed explanation of any particular step!
