Mindy Membrane
The Gatekeeper
Mindy wraps around the entire cell like a stretchy bubble! She decides who gets in and who has to stay out.
What Mindy Does
Wraps around the whole cell to protect it
Helps control what moves in and out of the cell
Uses membrane proteins to help transport many substances
Helps the cell communicate with neighbors
Sodium Potassium Pump & Ion Channels
Mindy uses a special protein called the pump.
It uses energy from Mike Mitochondria to push sodium out of the cell and pull potassium into the cell.
Each time it works, the pump moves 3 sodium ions out and 2 potassium ions in. Because more positive charge leaves than enters, the inside of the cell becomes more negative than the outside.
This charge difference stores energy and keeps the cell ready to send signals.
When the cell receives a signal, sodium ion channels open, allowing sodium to rush back into the cell.
Afterward, potassium ion channels open, letting potassium slowly move back out so the cell is ready for the next signal.
Free Printables
Print or download these fun activities for Mindy.
Want to go deeper with Mindy?
Explore more in the Life in Cellville™ Complete Cell Biology Curriculum — Grades 3–8, with a 148-page Student Workbook, Teacher Guide & Answer Key, and 13 original science songs.
Explore the Complete CurriculumKeep Exploring Cellville
Keep exploring! Follow the crew members who work together, then try a story, song, or printable.