|University Federico II
of Naples, Italy
What is life? Over hundreds and hundreds years men have tried to find an answer to this question through philosophy, religion, poetry, art and, obviously, also science.
Focusing strictly on the scientific point of view, we can say that life of all living organisms, from the simplest bacteria to humans, is based on a very complex network of chemical exchanges.
All the fundamental functions, including breathing and reproduction, metabolism and eyesight, smell and taste, learning and emotion, feeling pain and pleasure, are the final effect of a finely tuned set of chemical reactions.
To unveil the details of such complex mechanisms, many years of experimental studies are needed. Thousand of biochemists over the world are involved in research projects and studies aimed to understand the structure, properties and reactions of living substances.
Biomolecules are involved into a complex network of reactions and chemical processes known as metabolism, which regulates the biosynthesis and degradation of the fundamental components of organisms, and also provides the energy necessary for life.
It is worth remembering, however, that organic substances, which make-up living organisms, are not different from inorganic ones, and follow the same laws. For their life, animals and plants exploit catalysis, acid-base interactions, redox reactions, electrostatic interactions and so on, i.e. the same kind of chemical processes characteristic of non-living matter.
Improvement of Biological sciences is a direct effect of the introduction of a chemical approach in this field. Most recent findings in Medicine about cancer and other widely-spread pathologies, as well as genetic manipulations, assisted reproduction, biotechnological agriculture are among the important results achieved thanks to the application of Chemistry in Biology.
Chemistry studies structures, proprieties, and transformations of the molecules constituting the living organisms and the rules that regulate their interactions with other molecules.
Many components of living organisms, such as proteins, nucleic acids and polysaccharides are complex macromolecules (polymers) made-up by linking small building-blocks, such as aminoacids, nucleotides and sugars. Among biomolecules, an important role for both structural and functional properties of living organisms is also played by lipids, also called fats, which are quite a heterogeneous class of molecules from a chemical point of view.
|The DNA double helix|
The shape of molecules, i.e. their 3D structure, is a crucial aspect in all biological processes. Before any chemical reactions may occur, the molecules have to interact each other very specifically, and their shape is very important for binding selectivity.
On the other hand, knoweledge of the 3D structure can be helpful to disclose functional aspects. The structure of DNA, solved by Watson and Crick, represented a milestone on the way to understand the mechanism of transmission of genetic information.