Breathing is the movement of air in and out of the body, and cellular respiration is the release of energy from glucose inside cells. One supplies oxygen, and the other uses it.
This lesson closes the SPM Biology cellular respiration chapter. It builds on comparing aerobic and anaerobic respiration.
How do the two processes compare?
| Breathing | Cellular respiration | |
|---|---|---|
| Type of process | Physical | Chemical |
| Where | Lungs, diaphragm, rib muscles | Cytoplasm and mitochondria of cells |
| What happens | Air moves in and out | Glucose is broken down |
| Result | Gas exchange with the air | Energy is released |
| Who does it | Animals with lungs | Every living cell, including plants |
Use “lungs” only for breathing, and “cells” for respiration.
Worked example: fixing a sentence
A student writes: “Respiration happens in the lungs, where oxygen is used to make energy.”
There are three problems in that one sentence.
- Respiration happens in cells, not in the lungs.
- The lungs do the gas exchange, which is part of breathing.
- Energy is released from glucose, not made.
A correct version: “Breathing brings oxygen into the lungs. The blood carries it to the cells, where aerobic respiration releases energy from glucose.”
The mistake that costs marks
The common slip is to use the two words as if they mean the same. A question that asks about “respiration” is usually about what happens in the cell.
| Wrong | Right | |
|---|---|---|
| Location | Lungs | Cells |
| Energy | Made by breathing | Released by respiration |
| Plants | Breathe | Respire, without breathing movements |
If the word “lungs” appears in a respiration answer, stop and check whether the sentence is about breathing.
Check yourself
Decide whether each statement describes breathing or cellular respiration.
- The diaphragm moves down.
- Glucose is broken down in the mitochondria.
- Air moves into the lungs.
- Energy is released in a cell.
Answer
- Breathing. The diaphragm is a breathing muscle.
- Cellular respiration. The mitochondria are in cells.
- Breathing. Air moving into the lungs is a physical process.
- Cellular respiration. Energy release from glucose happens in cells.
What to study next
Test the whole chapter in the cellular respiration practice set. Practise reading results with the biological data interpretation trainer, and log slips in the mistake log and paper-error review.
If you want a teacher to check your wording, see online one-to-one Biology tuition.