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Explain Bot mRNA (messenger RNA) and tRNA (transfer RNA) play essential roles in the process of protein synthesis. Let me explain how they work together step by step:
1. Transcription: The process begins in the nucleus of a cell, where the DNA sequence that codes for a particular protein is first transcribed into mRNA. This process is carried out by an enzyme called RNA polymerase.
2. mRNA Processing: Once transcribed, the newly formed mRNA undergoes a series of modifications, including the removal of non-coding regions called introns and the addition of a protective cap and a poly-A tail. This processed mRNA is then ready to leave the nucleus and enter the cytoplasm where protein synthesis takes place.
3. Translation: Once in the cytoplasm, the mRNA binds to a ribosome, which serves as the site of protein synthesis. The ribosomes have two subunits, the large and small subunits, and the mRNA is positioned between them.
4. Initiating Protein Synthesis: Translation starts with the binding of a specific tRNA molecule to the start codon on the mRNA. The tRNA molecule carries a complementary anticodon sequence and is specific to a particular amino acid.
5. Elongation of the Protein Chain: As the ribosome moves along the mRNA, additional tRNA molecules bind to the codons in the mRNA sequence. Each tRNA brings in the corresponding amino acid to the growing protein chain. The ribosome links the amino acids together through peptide bonds, forming a polypeptide chain.
6. Termination and Release: The process continues until a stop codon is reached on the mRNA. At this point, no tRNA molecule matches the codon, and a release factor binds instead. This causes the ribosome to detach from the mRNA, releasing the completed protein.
In summary, mRNA carries the genetic information from DNA to the ribosomes, serving as the template for the synthesis of proteins. tRNA molecules, with their specific anticodon sequences, bring in the appropriate amino acids to the ribosome, where they are joined together to form a protein chain.