The Secret Life of Cells
Like Duolingo, but for The Secret Life of Cells. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
For the part of you with thirty open tabs that never became anything.
Free forever · No credit card · iPhone & Android

Key ideas in The Secret Life of Cells
- The cell as the fundamental unit of life
- The relationship between single-celled and multicellular life
- The fundamental unit of life
- Cells are constantly active, not static or 'still' inside
- The nucleus stores the genetic instructions for the cell
- Thousands of different chemical reactions occur at the same time in a tiny space
- Mitochondria convert nutrients into usable energy
- The membrane controls what enters and exits the cell
- Constant motion and reaction are required to keep the cell from breaking down
- Organelle functions using the city analogy
- The dynamic nature of cellular chemistry
- Life isn't a special ingredient, but a result of how molecules interact
- Individual molecules follow the laws of chemistry, but the whole system follows the laws of biology
- Organization is the key difference between a living cell and a bowl of biological soup
- Life as an emergent property of molecular organization
- Visible light has a physical width (wavelength)
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives The Secret Life of Cells the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
What is true about all living things, regardless of their physical size?
Get it right to open this lesson and 39 more in the app.
Where The Secret Life of Cells takes you
Explore the microscopic world within you, where tiny biological machines work tirelessly to keep you alive. Learn how cells build, power, and repair themselves in this comprehensive guide to the building blocks of life.
- 1
The Living City
- The Cell as a Microscopic Machine
- Seeing the Invisible
- 2
The Border and the Interior
- The Plasma Membrane: The Smart Gatekeeper
- The Cytoskeleton: Scaffolding and Highways
- The Cytosol: The Crowded Soup of Life
- 3
Energy and Manufacturing
- Mitochondria: Converting Fuel to Energy
- The Protein Factory: Ribosomes and the ER
- The Golgi Apparatus: Packaging and Shipping
- 4
The Command Center
- The Nucleus: The Master Library
- DNA and RNA: The Blueprints of Life
- 5
Life Cycles and Communication
- Cell Division: How One Becomes Two
- Cell Signaling: How Cells Talk
- Specialization and Death
5 sections · 13 units · 40 levels. Built to play, not to enroll.
You pick the voice
The Secret Life of Cells is taught in the The Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
More Science on Tomo
Human Anatomy and Physiology
Go beyond basic diagrams to master the complex mechanical and chemical interactions that sustain human life. This course bridges the gap between structural form and clinical function for a professional-grade understanding of the body.
Atmospheric Physics: The Secret Life of Clouds
Move beyond basic classification into the complex thermodynamics and microphysics that drive cloud formation and global climate regulation.
Stargazing and the Hidden Universe
Learn to read the night sky like a map and discover the secret messages hidden in starlight. From finding famous constellations to 'seeing' invisible radiation, you'll view the cosmos in a whole new light.
Cellular Bioenergetics and Metabolic Flux
A master-level exploration of the molecular machinery, thermodynamic constraints, and regulatory networks that govern how cells extract and transform energy.
Quantum Realities: Time and Parallel Worlds
Move beyond science fiction to explore the rigorous physics of the multiverse, retrocausality, and the mathematical possibility of time travel. Master the mechanics of how reality branches and how time behaves at the quantum scale.
Biostatistics for Clinical Research
Move beyond basic averages to design rigorous studies and interpret complex medical data. Learn to handle bias, calculate power, and model survival outcomes like a professional researcher.
Start The Secret Life of Cells today.
Download Tomo, search The Secret Life of Cells, and play your first lesson in under a minute.