respiration – the process where living organisms release energy from glucose

To remember the meaning of respiration, use the following mnemonic:

While resting and wiping the perspiration (respiration) from my brow, I drank glucose to replenish the energy used. 

Respiration is a chemical process that occurs in all living cells to release energy from food molecules like glucose for muscle movement or plants to grow. There are two main types of respiration. One type is aerobic respiration, which uses oxygen and produces carbon dioxide and water as waste products. The other type is anaerobic respiration, which occurs without oxygen and produces different waste products like lactic acid in animals or ethanol in plants and yeast. The energy released is used for all life processes including growth, movement and maintaining body temperature. 

Respiration is different from breathing - breathing is just the physical process of getting oxygen into the body, while respiration is the chemical reaction that actually releases energy from food. 

In cells, respiration mainly takes place in the organelles called mitochondria, which is why mitochondria are often called "powerhouses" of the cell. 

To learn more about respiration, see our section on the topic here.