Biology / Unit 2 Bio 0257 short lesson, about 20 seconds
The Plasma Membrane, Introduced
Captions available
The idea
The plasma membrane is a phospholipid bilayer with embedded proteins that separates a cell's interior from its surroundings.
In practice
The membrane controls passage of organic molecules, ions, water, and oxygen inward while letting wastes like carbon dioxide pass out.
Where people slip
This entry names the membrane's structure; this unit's closing block covers exactly how each substance crosses it.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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