Principles of Biochemistry Volume 1 - A. Lehninger 1985

Biomolecules
Biochemistry: The Molecular Logic of Living Organisms
Biochemistry seeks to understand the nature of the living state

We might now ask: if Living organisms are composed of lifeless molecules, why is living matter so radically different from inanimate matter, which is also made up of inanimate molecules? Why is a living Organism something much more than merely the sum of its non-living components? Philosophers once explained this by suggesting that living organisms are endowed with a mysterious and divine life force. However, this doctrine, known as vitalism, was rejected by modern science, which seeks rational and, above all, testable explanations for natural phenomena. Biochemistry as a science sees its primary objective in determining how the lifeless molecules that make up living organisms interact with one another to maintain the living state and ensure its reproduction. Of course, biochemistry yields vital insights applicable in medicine, agriculture, the food industry, and manufacturing, yet its ultimate goal remains the unraveling of the mystery of life in all its concrete manifestations.

The molecules that make up living organisms obey all known laws of chemistry, yet beyond that, they interact with one another according to another system of principles, which we may collectively term the molecular logic of the living state. These principles do not necessarily represent any new physical laws or forces hitherto unknown to us. Rather, they should be viewed as a specific system of regularities that characterize the nature, Functions, and interactions of Biomolecules—that is, the molecules that constitute living organisms.

Let us now see if we can formulate any important principles regarding the molecular logic of the living state.