Free Cell Biology Guide

Cellula: A Simple Guide to Cells

Learn membranes, transporters, nutrients, mitochondria, ATP, waste, lysosomes, viruses, organelles, and survival. You do not need to own Cellula to learn from this guide, but the game lets you play the same systems.

1. What Is a Cell?2. The Cell Membrane3. Transporters in the Membrane4. Nutrients and Resources5. Mitochondria, Oxygen, and ATP6. Waste and Lysosomes7. Viruses and Infection8. The Nucleus9. ER and Golgi10. Cell Division and Growth11. Immune Defense and B Cells12. Lysis and Game Over13. What Cellula TeachesGlossary

1. What Is a Cell?

Simple biology

A cell is the smallest living unit of an organism. Some organisms are made of only one cell. Others, like humans, are made of trillions of cells working together. Every living cell faces the same basic problem: how does it stay alive? A cell must separate its inside from the outside world, bring in useful materials, make energy, build structures, remove waste, protect genetic information, and respond to danger.

How Cellula teaches it

In Cellula, you manage cells as survival systems. You begin with a simple cell and build the parts it needs to stay alive: membrane structures, transporters, organelles, cleanup systems, and defenses.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

2. The Cell Membrane

Simple biology

Every cell needs a boundary. The cell membrane separates the inside of the cell from the outside environment and controls what enters and leaves. The membrane is made mostly of phospholipids that form a flexible double layer called the phospholipid bilayer.

How Cellula teaches it

In Cellula, the membrane appears as the ring around the cell. It protects the inside while also needing transporters so useful materials can enter.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

3. Transporters in the Membrane

Simple biology

Many important molecules cannot simply drift through the membrane whenever they want. They need help from transporter proteins embedded in the membrane.

How Cellula teaches it

Cellula shows transporters as distinct membrane structures: red transporters move amino acids, blue transporters move glucose, and yellow skinny transporters move lipids. Different resources need different doors.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

4. Nutrients and Resources

Simple biology

Cells need glucose, amino acids, lipids, oxygen, ATP, proteins, and membrane materials. These resources are physical materials that must be gathered and used.

How Cellula teaches it

Cellula makes resources visible. If a cell lacks key materials, it cannot build organelles, repair itself, or keep growing.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

5. Mitochondria, Oxygen, and ATP

Simple biology

ATP is a major usable energy molecule. Mitochondria help many cells make large amounts of ATP by moving electrons through the electron transport chain. Oxygen accepts electrons at the end of that chain, allowing ATP production to continue efficiently.

How Cellula teaches it

In Cellula, red blood cells release Oâ‚‚ near the cell. Oxygen lets mitochondria keep producing ATP. Energy production also creates waste, so mitochondria must be supported by cleanup systems.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

6. Waste and Lysosomes

Simple biology

Cells are busy, and activity creates waste. Lysosomes contain digestive enzymes that break down waste, damaged cell parts, and unwanted material.

How Cellula teaches it

In Cellula, lysosomes clean up waste before it becomes dangerous. They can also destroy viral genetic material before it reaches the nucleus.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

7. Viruses and Infection

Simple biology

Viruses are not cells. They must enter living cells and use cellular machinery to make more copies. Many viruses begin by attaching to structures on the cell membrane and releasing genetic material.

How Cellula teaches it

In Cellula, bright green viruses can dock on receptors and release DNA or RNA. If viral genetic material reaches the nucleus, infection can take hold. A lysosome placed in the path can intercept it.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

8. The Nucleus

Simple biology

The nucleus stores most of the cell’s DNA. DNA contains instructions for building proteins and controlling cell activity. The nucleus is best thought of as a protected information center.

How Cellula teaches it

In Cellula, the nucleus is something the player must protect. If viral DNA or RNA reaches it, the cell may be lost.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

9. ER and Golgi

Simple biology

The endoplasmic reticulum helps make and process cellular materials. The Golgi apparatus receives materials, modifies them, sorts them, packages them, and sends them where they need to go.

How Cellula teaches it

In Cellula, the Golgi packages resources into vesicles and sends them toward the nearest cell. Survival is logistics.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

10. Cell Division and Growth

Simple biology

Cells can grow and divide, creating new cells. But division requires enough energy, membrane material, proteins, and working internal systems.

How Cellula teaches it

In Cellula, dividing creates another cell to manage. More cells can increase survival potential, but they also increase complexity.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

11. Immune Defense and B Cells

Simple biology

In multicellular organisms, immune cells help defend the body against threats. B cells can produce antibodies, which bind to specific targets and help fight invaders.

How Cellula teaches it

In Cellula, B cells appear as large purple immune cells with antibody-like structures. They help show that cells live in a larger battlefield.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

12. Lysis and Game Over

Simple biology

A cell can die when its systems fail. Lysis happens when the cell breaks open and can no longer maintain the separation between inside and outside.

How Cellula teaches it

In Cellula, waste, infection, energy problems, or structural failure can cause a cell to lyse. Failure becomes information about which system broke.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

13. What Cellula Teaches

Simple biology

Biology is not just vocabulary. A living cell is a system: borders, transport, energy, waste, defense, information, logistics, and growth all interact.

How Cellula teaches it

Cellula turns those ideas into play. The player learns by keeping a cell alive.

What you learn: Cells survive because many systems work together. The part matters because of the job it performs in the living loop.

Glossary

Amino acids: building blocks of proteins.

ATP: the cell’s main usable energy molecule.

Cell membrane: flexible boundary around the cell.

DNA: molecule that stores genetic instructions.

Golgi apparatus: organelle that packages and ships materials.

GLUT1: a glucose transporter used as an entry point in Cellula.

Lysosome: organelle that breaks down waste and unwanted material.

Mitochondrion: organelle that helps make large amounts of ATP using fuel and oxygen.

Nucleus: protected information center of the cell.

Oxygen / Oâ‚‚: accepts electrons at the end of the mitochondrial electron transport chain.

Phospholipid bilayer: double-layer membrane structure.

Virus: infectious particle that must enter living cells to reproduce.