Biology · Interactive
Cellular Respiration
How every living cell releases energy from food. Tap the parts of the equation and the cell to explore, then test yourself at the end.
The equation
Cells break down glucose using oxygen to release energy. Tap each part.
| Atom | Reactants | Products | Match |
|---|---|---|---|
| Carbon (C) | 6from C6H12O6 | 66 × CO2 | ✓ |
| Hydrogen (H) | 12from C6H12O6 | 126 × H2O = 6 × 2 | ✓ |
| Oxygen (O) | 186 + (6 × 2) = 6 + 12 | 18(6 × 2) + 6 = 12 + 6 | ✓ |
Atoms are rearranged, not created or destroyed, so every atom on the left turns up on the right. Energy isn't matter, so it doesn't count as atoms.
Where it happens
Tap a part of this animal cell.
With and without oxygen
When there isn't enough oxygen, some cells can still release a little energy.
ATP made from one glucose
Older textbooks say aerobic respiration makes 36–38 ATP. Better measurements give about 30–32.
Photosynthesis vs respiration
The two equations are the reverse of each other, but they are not the same process run backwards.
⚠️ Breathing isn't respiration
Breathing moves air in and out of your lungs. It's how your body gets oxygen in and carbon dioxide out.
Cellular respiration is a chemical reaction that happens inside every one of your cells. Breathing supplies it with oxygen. Plants respire too, even though they don't have lungs.
💡 Did you know?
Quick check
Six questions. You'll see why after each answer.