1Two different things
Breathing is a physical process: muscles move air in and out of the lungs. Respiration is a chemical reaction inside every cell. Breathing brings in the oxygen that respiration uses.
breathingrespiration
Lesson 22.2 notes
Breathing and respiration
Breathing isn't respiration: how oxygen and glucose reach the cells, how carbon dioxide leaves, and why breathing and heart rate rise in exercise.
2Oxygen to the cells
Oxygen passes from the air in the lungs into the blood. Red blood cells carry it round the body to every cell, where it is used in respiration.
red blood cells
3Glucose to the cells
Carbohydrates in food are digested into glucose. It is absorbed into the blood in the small intestine and carried, dissolved in the plasma, to every cell.
plasma
4Carbon dioxide out
Respiration makes carbon dioxide, a waste product. The blood carries it from the cells to the lungs, where it passes into the air and is breathed out.
waste
5Exercise
When you exercise, your muscle cells respire much faster, to release the extra energy for contracting. They need more oxygen and glucose, and make more carbon dioxide.
exercise
6Breathing rate and heart rate
Your breathing rate rises, taking in more oxygen and getting rid of more carbon dioxide, and your heart rate rises, pumping blood to the muscles faster.
breathing rateheart rate
7Holding your breath
You can stop breathing for a short while. Respiration carries on: your cells keep using the oxygen in your blood. As carbon dioxide builds up, you soon have to breathe again.
Explore: Exercise lab
Change how hard the body is working and watch the breathing rate, the heart rate and the muscle cells respond. Then hold your breath.
Common mistake: Breathing is not respiration
People often say 'respiration' when they mean breathing. Breathing moves air in and out of the lungs. Respiration is the chemical reaction in every cell that releases energy. Breathing supplies the oxygen that respiration needs.
Remember
- Breathing is a physical process: muscles move air in and out of the lungs. Respiration is a chemical reaction in every cell.
- Oxygen is carried by red blood cells; glucose is dissolved in the blood plasma. Carbon dioxide travels back to the lungs in the blood.
- In exercise, muscles respire faster, so breathing rate and heart rate rise to supply more oxygen and remove more carbon dioxide.
Going further at GCSE