Translation
Concept Development
Once the students understand the process of transcription, you can then move on to translation. However, before students can fully be able to understand this process you must first introduce them to the genetic code.
The Genetic Code
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Image retrieved from -http://voer.edu.vn/c/the-genetic-code/d4223f39/c5e4f324
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Translation
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Additional Information:
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Ribosome recognizes the 5' cap causing the small and large subunit to come together clamping the mRNA in place. The first codon recognized is typically AUG which means a Methionine (Met) will bind to the P site.
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The next tRNA binds to the A site and a peptide bond is formed between the two amino acids (Met and Ala for this example).
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Ribosome translocates one codon over, releasing the tRNA from the P site and binding the next tRNA with the corresponding amino acid to the A site.
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Same process repeats which lengthens the polypeptide chain.
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Process continues until a stop codon is reached. There is no tRNA associated with a stop codon but instead it signals a release factor protein to aid in the dismantling of the ribosome-mRNA complex.
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The polypeptide is released and the ribosome is free to bind another mRNA transcript.
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Some details to keep in mind:
Image retrieved from- http://www.bio.miami.edu/dana/250/250SS13_9print.html
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Misconceptions
The biggest misconception that students have with the process of translation is regarding the wobble hypothesis. Before students are introduced to this term, they believe that the codon (say for instance UUG) must be matched with its complimentary base pairs on the anticodon of the tRNA molecule (AAC). Although this seems like a logical belief, it is important that you introduce the wobble hypothesis to your students and go over it with them by using a few different examples. The wobble hypothesis is the idea that there is flexibility between the codons and anticodons when they are binding, which allows for binding to still occur despite the 3rd base pair on the codon being different different. For instance, the anticodon AGU could bind the codon UCA (normal pairing) or it could bind UCG (wobble pairing). Overall, the best way to address this misconception with your students is to provide them with plenty of examples to show them the difference between normal pairing and wobble pairing due to the wobble hypothesis.