Protein Translation and Post-Translational Modifications Quiz

Translation Initiation Phase

• The initiation phase marks the beginning of translation, where the small ribosomal subunit binds to the mRNA
• The first tRNA, carrying the amino acid methionine, binds to the start codon (AUG) on the mRNA
• The large ribosomal subunit then joins the complex, forming a complete ribosome

Translation Elongation Phase

• The elongation phase involves the addition of amino acids to the growing polypeptide chain
• Amino acids are brought to the ribosome by tRNA molecules, which recognize the codons on the mRNA
• Peptide bonds are formed between consecutive amino acids, elongating the polypeptide chain

Stop Codon and Termination

• When a stop codon (UAA, UAG, or UGA) is reached during translation, protein synthesis is terminated
• The ribosome releases the completed polypeptide chain, and the mRNA is released from the ribosome
• The ribosome then dissociates into its large and small subunits, marking the end of translation

Role of the First tRNA

• The first tRNA, carrying the amino acid methionine, plays a crucial role in translation initiation by binding to the start codon (AUG) on the mRNA
• This binding is necessary for the assembly of the ribosome and the initiation of protein synthesis

Role of the Ribosome During Termination

• During the termination phase, the ribosome releases the completed polypeptide chain and the mRNA
• The ribosome then dissociates into its large and small subunits, allowing it to recycle for further translation events