Biochemistry

Biochemistry is the science that studies the chemistry of processes that take place in living creatures and make life possible. The term biochemistry only became widely used in the early part of the 20th century; the subject had previously been known as biological chemistry or physiological chemistry. Important areas of biochemistry include the study of digestion and of the differences between intake and outflow of energy in different forms in living creatures and the identification of the component parts of and chemical reactions within blood. Biochemistry also improves our understanding of the role and composition of hormones and genes and helps explain the nature of evolution in chemical terms.

All of life depends on a series of critical chemical reactions. The process of photosynthesis, for example, [Page 228]by which plants convert sunlight into energy, is a fundamentally chemical process. Animal life depends on the ingestion of food (generally a physical action) and then the conversion of that food into energy through digestion, which is a series of chemical reactions that break down the food into a variety of chemicals that may power the animal or else be eliminated as waste. All of the many chemical reactions involved in this process may be considered metabolism.

Metabolism, in turn, depends on the presence of enzymes, which are chemicals present in large numbers in all complex living creatures and which are created and regulated by genetic information contained within DNA and within cells. It is difficult to isolate biochemistry from the many other fields of science with which it is linked. This complexity suggests the need for cooperation between scientists from different fields and the importance of creating cross-disci-pline teams.

The possibility of contemplating a body of knowledge and investigation to be known as biochemistry was not possible before chemistry itself was properly established as a body of knowledge. It was only when scientists such as Robert Boyle and Antoine-Laurent Lavoisier pioneered the field of chemistry that its impact on the biological sciences began to be recognized. Subsequently, scientists such as Louis Pasteur were able to identify the interaction between chemistry and biology on a firmly experimental basis. What was identified by experiment has been brought into the realm of theory. Improvements in equipment and documentation, as well as in the distribution of information and findings by computer networks, have enabled complex and sophisticated examinations that were not possible until recent decades. Genome sequencing, for example, requires experimental data gathering and analysis of such intensity that it would have been almost unimaginable until very recently.

Advances in biochemistry have helped explain how creatures living in different environments survive, while providing insights into the ways in which life might flourish in alien contexts. This understanding is constantly changing with new discoveries about the extreme conditions in which life exists on earth—in-cluding in much higher temperatures and much deeper under the surface of the sea than had previously been believed.