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Guilherme Mazui

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What is the Difference Between Start Codon and Stop Codon?

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The main difference between a start codon and a stop codon lies in their roles in the protein translation process:

  • Start Codon: This is the site where protein translation initiates. The start codon interacts with initiation factors or nearby sequences to start the translation process. In eukaryotes, the most common start codon is AUG, which codes for methionine. The starting sequence is usually preceded by the 5'UTR (untranslated region).
  • Stop Codon: This is the site that marks the termination of the translation process. A stop codon can individually initiate the termination. The stop codon disassociates the ribosomal subunits, thus disrupting the amino acid chain. The standard stop codons are UAG, UAA, and UGA.

In summary:

Feature Start Codon Stop Codon
Role Initiates protein translation Terminates protein translation
Location 5' end of mRNA 3' end of mRNA
Codon AUG (codes for methionine) UAG, UAA, UGA (do not code for amino acids)
tRNA with anticodons Present Absent
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  • What is the Difference Between Start Codon and Stop Codon?
  • Comparative Table: Start Codon vs Stop Codon

    • Comparative Table: Start Codon vs Stop Codon

    Start codons and stop codons are essential elements in the process of protein synthesis. Here is a table highlighting the differences between them:

    Feature Start Codon Stop Codon
    Function Initiates the protein translation process Terminates the protein translation process
    Common Sequence AUG UAG, UAA, UGA
    Interaction Interacts with initiation factors or nearby sequences to initiate translation Dissociates ribosomal subunits, disrupting the amino acid chain
    tRNA Binding Associates with tRNA having anticodons tRNA with anticodons are absent

    The start codon, typically represented by the sequence AUG, signals the beginning of protein synthesis and also codes for the amino acid methionine. On the other hand, stop codons, represented by the sequences UAG, UAA, and UGA, mark the end of the translation process.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.