In this article we will discuss about Life as Complex Organization of Biomolecules.
Living organisms are composed of lifeless molecules. On isolation, the molecules behave like inanimate matters. The cell is the fundamental unit of organization through which life is expressed. It possesses intricate internal structures containing many kinds of complex molecules called the biomolecules.
These biomolecules are the products of evolutionary selection and they are the fittest possible molecules for the biological functions they perform. They interact with each other in specific relationship which is called the molecular logic of the living state. Living systems are highly organized structures and this organization takes a number of forms.
All organic biomolecules are ultimately derived from very simple environmental precursors like CO2, H2O and N2. These precursors are metabolically converted by the living world into the building- block biomolecules which are organic compounds of somewhat larger molecular weight. These building-block molecules are then covalently linked to each other to form the macromolecules.
In all living systems there are at least two types of bio-macromolecules — nucleic acids and proteins. They are also known as informational macromolecules. The nucleic acids are long polymers of four or more types of nucleotides arranged in a specific information-rich sequence.
They universally store and transmit genetic information’s. Proteins, on the other hand, are the products of gene action. They are also very large polymerized molecules of amino acids.
The functional state of these molecules is the unique three-dimensional conformation. Thus, the molecular organization is reflected not only in a specific covalent structure but also in higher order structural forms. Some proteins perform specific catalytic functions as enzymes and others serve as structural elements.
Further, the bio-macromolecules are themselves organized into much larger and more complex structures which appear crucial for many of the metabolic processes characteristic of living systems. For example, the biological membranes contain many kinds of proteins as well as lipids that are arranged in a highly organized way. The assembly exhibits many properties not found in its individual constituents.
In the next higher level of organization a cell consists of subcellular structures made up of membranes as well as free protein molecules and other constituents, Each of these structures perform particular functions of the cell in a very harmonious way. Other important biomolecules are carbohydrates, fats and oils, chlorophyll and several other components of cells.