Cellular Respiration
Cells break down glucose to release ATP.
About this topic
Cellular respiration releases energy from glucose to make ATP: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (about 30–32 ATP). Stages: glycolysis in the cytoplasm, the Krebs cycle in the mitochondrial matrix, and the electron transport chain on the inner membrane, where most ATP is made.
It is happening in all living cells all the time, in plants as well as animals. Breathing supplies oxygen and removes CO₂, and the energy supports movement, warmth and growth.
Imagine eating a banana before a run. Glucose is broken down in glycolysis to two pyruvate, producing a little ATP; pyruvate enters the mitochondrion, where the Krebs cycle strips off electrons and releases carbon dioxide, and the electron transport chain uses these electrons and oxygen to make most of the ATP, forming water. You exhale the carbon dioxide.
Heat is also released, which is why exercise warms you and why compost heaps become hot. A common misconception is that respiration and breathing are the same; breathing brings oxygen to the cells that need it for respiration. Another is that plants only photosynthesise; they also respire. Compare the equation with photosynthesis: they are almost opposites.
Key ideas
- C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
- Stages: glycolysis, Krebs cycle, electron transport
- Needs oxygen
Quick check
Use cases: where Cellular Respiration helps
- Homework: review the key idea behind Cellular Respiration before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Cellular Respiration without notes.
- Visual learning: play with the interactive lab to see how Cellular Respiration changes when you adjust its inputs.
- Teaching a friend: explain Cellular Respiration in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Cellular Respiration?
Cells break down glucose to release ATP.
What will I learn in Cellular Respiration?
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP. Stages: glycolysis, Krebs cycle, electron transport. Needs oxygen.
Is Cellular Respiration part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Cellular Respiration lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Cellular Respiration?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.