Mistake Master
Mistake Master · AP Biology · Unit 2 · Step-Through Animation
Too Big for the Tunnel
You'll learnwhy bulk transport, not a channel, moves cargo too big to fit a pore.
A white blood cell swallows a whole bacterium — a thousand times wider than the widest pore in its membrane. Nothing goes through. Instead the membrane itself bends, wraps the cargo, and pinches off a vesicle, and it costs ATP even though no pump ever turns. Twelve short steps; press Next for each one.
too big for any pore · the membrane wraps it · always ATP
Before you start
What you're looking at
A membrane at scale: a channel protein threading a tiny glucose molecule, and a bacterium a thousand times wider arriving beside it.
The question
How does a cell take in cargo far too large for any pore?
Step 1 / 12