1. mRNA Transcription:
* DNA is transcribed into messenger RNA (mRNA) in the nucleus. This mRNA molecule contains the genetic code for a specific protein.
2. mRNA Processing:
* The mRNA molecule undergoes processing. This includes adding a 5' cap and a poly-A tail, as well as splicing out non-coding regions called introns.
3. mRNA Transport:
* The processed mRNA moves out of the nucleus and into the cytoplasm, where the ribosomes are located.
4. Ribosome Binding:
* The mRNA molecule binds to a ribosome. Ribosomes are complex structures made of ribosomal RNA (rRNA) and proteins. They act as the "factory" for protein synthesis.
5. tRNA Binding and Codon Recognition:
* Transfer RNA (tRNA) molecules carry specific amino acids. Each tRNA molecule has an anticodon that complements a specific codon (three-nucleotide sequence) on the mRNA.
* The ribosome reads the mRNA codons one at a time, and the corresponding tRNA molecules bring in the correct amino acids.
6. Peptide Bond Formation:
* As the ribosome moves along the mRNA, the amino acids are linked together by peptide bonds. This creates a growing polypeptide chain.
7. Termination:
* The process continues until the ribosome reaches a stop codon on the mRNA. At this point, the polypeptide chain is released from the ribosome.
8. Protein Folding and Modification:
* The newly synthesized polypeptide chain then folds into a specific three-dimensional structure, guided by interactions between its amino acids. This structure is essential for the protein's function.
* The protein may undergo further modifications, such as glycosylation or phosphorylation, before it is ready to perform its role in the cell.
In summary, translation is a complex process that involves decoding the genetic information in mRNA and using it to assemble a chain of amino acids that folds into a functional protein.
