Question: do flowers breathe? and if they do how do they do it.

Susan Skelton answered on 21 Nov 2013:

Hi again, theboss!
No, plants don’t breathe, but they do respire. All living things get the energy they need to live from a chemical reaction called respiration. Just like animals, if plants stop respiring, they will die.

Respiration is a process that happens in the cells, where the cells use glucose as a starting point and use it to make energy to live and grow.

The word equation that describes what happens during respiration is:
glucose + oxygen → carbon dioxide + water (+ energy).

So during respiration, plants take in glucose and oxygen, and use them to make carbon dioxide, water and energy.

Plant cells are undergoing respiration all the time; the cells are always making energy to keep them alive. But they also do another process too, called photosynthesis.

For photosynthesis, the word equation is:
carbon dioxide + water (+ light energy) → glucose + oxygen.

This is the opposite of the respiration process! But photosynthesis needs some light energy (on the left hand side of the equation) to make it work, so plants only photosynthesise when there is lots of sunlight.

That means at night, when it is dark, plants do respiration and no photosynthesis, and in the daytime, plants do lots more photosynthesis than respiration!

Because they are very efficient at photosynthesis, overall, plants produce more oxygen than carbon dioxide, so in normal light conditions plants can turn carbon dioxide in the air into oxygen which we humans need to breathe. That’s why it’s a good idea to plant trees in polluted areas like cities: they help to clean up all the carbon dioxide in the air.