Share Cells and microbes
Save to Folder
Plants, animals, and microbes need energy to stay alive. The cells of all living things take this energy from food.
Mitochondria are tiny parts inside the cytoplasm of all cells, and they take energy from food.
Cells that use a lot of energy, like the cells in muscle tissue and nerve tissue, have a lot of mitochondria.
Inside the mitochondria, chemical reactions happen between oxygen and sugar.
These reactions release energy from food.
When living things use oxygen to release energy from food, it’s called respiration.
There’s only very little oxygen in water at the bottom of the ocean. Microbes that live here can get energy from their food without oxygen.
Plant and animal cells use oxygen from the air for respiration.
Plants take in oxygen for respiration through the stomata holes on their leaves.
People and other animals take in oxygen by breathing it in through their mouth or nose.
When animals move very fast, like when people run in a race or play a fast game of soccer, their muscle cells use a lot of energy.
These cells need more energy from food so that they can keep working.
So animals start to breathe faster to take in more oxygen for respiration.
The cell membrane controls what goes in and out of every cell.
It lets oxygen and sugar come into the cell for respiration.
All chemical reactions make waste.
