Biology / Unit 6 Bio 1271 short lesson, about 20 seconds
The 5' Cap
Captions available
The idea
A eukaryotic pre-mRNA's 5' end is capped with a modified guanine shortly after transcription begins, protecting the RNA from degradation.
In practice
The 5' cap is added while RNA polymerase II is still transcribing the gene, not after transcription finishes.
Where people slip
The 5' cap is added at the RNA's 5' end specifically — the corresponding 3' end is protected by a separate modification.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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