Cell Size Sim - Cell Simulator

Cell Simulator

Hello! I'm Julian, a researcher in Dr. Biology's lab. My specialty is building scientific computer models.

Now that you've learned the background information, it's time to dive deeper into what actually controls the cell size and nucleus size inside the cell. This is where you can really start thinking like a scientist by following the steps of the scientific method to run your own experiments.

The model of the cell below lets you control the number of small particles and large particles inside the cell.

Follow the steps of the scientific method using this model to predict what will happen when you make changes to the number of small and large particles.

Do you remember the steps of the scientific method? Run at least 3 different experiments using those steps. You can download and print the scientific method worksheet (PDF) to write down your answers.

About the Cell Simulator

This simulator shows a cell and its nucleus, filled with molecules that make up the inside of the cell. Only a small number of molecules are shown in this simulator. In reality, there are many billions of molecules quickly moving around within the cell.

Moving particles create osmotic pressure on the nuclear membrane and the cell membrane. This pressure determines the size of the nucleus and the cell.

The nucleus has a semipermeable membrane. This means that only certain molecules can pass through, while others cannot.

One important number to look at when talking about cell sizes is the NC ratio. This number represents how much of the cell the nucleus takes up.

There are large and small particles (such as ions) inside the cell. The small particles (orange) are located throughout the cell. They can pass through the semipermeable membrane of the nucleus. Small particles affect the cell size.

There are fewer large particles than small particles inside the cell. In this simulation, there are always 200 large particles total inside the cell. They are located in the cytoplasm (pink particles) and inside the nucleus (blue particles). Large particles create the pressure that determines the NC ratio. In a real cell, these larger particles would not cross the semipermeable membrane of the nucleus. In this simulation, you have the ability to change the location of the large particles to see how this would impact the cell.

In the simulation below, you can change the number and distribution of particles inside the cell to see how this changes the cell size and nucleus size.

For this model, the three-dimensional cell has been projected onto a two-dimensional plane.