External respiration and Internal respiration

Explanation

In external respiration, there is uptake of oxygen from the surrounding environment (air or water medium) and elimination of carbon dioxide into that medium. The exchange of gases takes place by diffusion across the general body or respiratory surfaces. It is a purely physical process and in this process no energy is produced. In internal respiration, there are both oxidative and nonoxidative enzymatic reactions by which energy is made available to maintain the various vital activities. It is a physico-chemical process and in this process energy is produced.