Note D — Chapter II · THE PROCESS OF LIFE.
Reading edition
It will be well here to introduce the technical terms for these changes. The general term for chemical actions occurring in the tissues of a living creature is metabolism; where the change is of such a nature that complex and unstable compounds are built up and stored for a while, it is called anabolism; where complex unstable compounds break up into less complex and relatively stable compounds, the term katabolism is applied. We shall speak of anabolic changes as constructive; katabolic, as disruptive, or sometimes, explosive.