Endocytosis brings things in, exocytosis sends them out
- The idea
- Predict
- See it
- Why
- Check
The idea
“Endocytosis is when a vesicle fuses with the membrane and dumps its cargo outside.”
Both words describe a vesicle at the plasma membrane, and the names differ by a couple of letters. It's easy to remember the picture and forget which way it runs.
The short version
The mistake: Endocytosis is when a vesicle fuses with the membrane and dumps its cargo outside.
What's actually true: Endocytosis pinches off membrane to bring material in. Exocytosis fuses a vesicle with the membrane to send material out.
- Endocytosis brings material in. The plasma membrane folds around it and pinches off as a vesicle inside the cell.
- Exocytosis sends material out. A vesicle, often from the Golgi, fuses with the plasma membrane and empties outside.
- A vesicle is a bubble of membrane. Exocytosis adds it to the cell surface, and endocytosis takes it away.
On the exam: Endo means in, exo means out. Ask where the cargo ends up, then pick the name that matches.