Biology / Unit 6 Bio 1279 short lesson, about 20 seconds
The 5' and 3' Untranslated Regions
Captions available
The idea
A mature mRNA's untranslated regions flank the coding sequence, upstream of the start codon and downstream of the stop codon.
In practice
The 5' region sits between cap and start codon; the 3' region sits between stop codon and poly-A tail.
Where people slip
An untranslated region is still transcribed and spliced with the mRNA — only its translation into protein is what it lacks.
Your place on the trail
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