Biology / Unit 9 Bio 1901 short lesson, about 20 seconds
Virion Structure: Genome, Capsid, and Envelope
Captions available
The idea
A virion holds a nucleic acid genome inside a protein capsid, sometimes wrapped in a lipid envelope taken from a host cell.
In practice
Influenza's genome sits inside an enveloped capsid; poliovirus's genome sits inside a capsid alone, with no envelope.
Where people slip
A virion has no ribosomes or organelles of its own— any envelope it carries is borrowed from a host cell.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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