Breathing and Gas Exchange

Respiration and gas exchange

Energy for all life processes of plants and animals is provided by biological oxidation reactions. In these reactions, hydrogen atoms are transferred from one molecule (donor) to another (acceptor). In most living organisms, the final acceptor of hydrogen is oxygen, which is converted into water.

Since the supply of oxygen in the body is small, its continuous delivery to the cells is necessary. Without oxygen, cells, especially the brain, quickly die. The metabolic process also produces carbon dioxide, which must be removed from the body.

The term "respiration" refers to the processes of consuming oxygen and releasing carbon dioxide, and converting energy into a form available for use by the cell. There are:

1. External breathing is the process of inhalation and exhalation.

2. Gas exchange is the exchange of gases between the cell and the environment.

3. Cellular respiration - enzymatic reactions involving oxygen in the cell.