BIOCHEMISTRY

BIOCHEMISTRY, the chemical investigation and explanation of biological processes. American biochemistry acquired its institutional base as a result of the medical reform movement during the Progressive Era and was characterized until World War II by its emphasis on applied research and close association with medicine. American biochemists have been involved in the testing of foods and drugs, the development of diagnostic tests and medical treatments, and the production of consumer goods ranging from synthetic fibers and biological detergents to vitamin supplements and the contraceptive pill. Since the 1970s, biochemists have been actively engaged in biotechnological enterprises.

Biochemistry's antecedents lie in nineteenth-century Europe, where the rise of organic chemistry and experimental physiology generated much investigation into the chemical constituents of living organisms and the chemical changes associated with physiological functions. The many American scientists who trained in European laboratories imported these practices into the United States, where research in animal chemistry, agricultural chemistry, medical chemistry, and physiological chemistry gained a firm foothold in agricultural research stations, hospitals, colleges, and universities.

In the early 1900s, investigators in Europe and America sought to unite the diverse fields dealing with the chemistry of life under name of "biochemistry" or "biological chemistry" (then the preferred term in the United States). Among the first journals expressing this aim was the Journal of Biological Chemistry, founded in the United States in 1905. The American Society of Biological Chemists was constituted in 1906. In the same decade, many American medical schools, newly under university control, began to teach biochemistry as part of a nationwide reorganization of preclinical education. By 1920, most American medical schools had established departments of biochemistry where research had a predominantly clinical orientation.

Early American biochemists led in the development of new analytical methods for determining chemicals in the body that were used to diagnose specific diseases and monitor physiological states. Otto Folin at Harvard, Donald D. Van Slyke at the Rockefeller Institute Hospital in New York, and Stanley Benedict at Cornell acquired international renown. The widespread use of techniques they developed led simultaneously to redefinitions and reclassifications of diseases in chemical terms.

A second prominent stream of American biochemistry, that of nutritional investigation, built on established strengths in agricultural research, especially at experimental stations in Connecticut and Wisconsin. Recognition of the importance for health of vitamins stimulated much American research into the distribution of vitamins in foods, their chemical properties, and their role in metabolism. Diseases identified as resulting from vitamin deficiencies in the diet, such as rickets, scurvy, and pellagra, were cured and prevented by specific dietary changes. Commercially produced vitamin preparations and vitamin-fortified foods were widely promoted among the public from the 1920s and became an important source of profit for the American food and pharmaceutical industries.

In the 1930s, some American centers began to develop biochemistry as a broad, fundamental biological science, after the model of leading German, English, and Scandinavian schools. A similar vision was promoted by Warren Weaver, who, as manager of its Natural Sciences Division, turned the Rockefeller Foundation into the major international funding body for basic research in bio-chemistry and biophysics. In this decade, the biochemistry department at Columbia University in New York, headed by Hans T. Clarke, became the largest and most influential American school of basic biochemical research.

Clarke gave place in his department to an exceptionally high number of biochemists who had escaped national socialist regimes in Europe and who brought their distinctive research styles with them. Among them was Rudolf Schoenheimer, who, at Columbia, was responsible for a milestone in twentieth-century biochemistry: he introduced the use of isotopes as labels that allow biochemists to follow in detail how, and at what rate, specific molecules undergo change in metabolic reactions. His re-search with David Rittenberg and Sarah Ratner not only heralded the use of what has since become an indispensable tool in the life sciences but showed that all cell constituents are in constant flux: molecules are continuously being broken down and rebuilt from the foods organismsingest.

During World War II, biochemists participated in the war effort in major ways. For example, American biochemists were involved in the large-scale production of penicillin, other antibacterial drugs, and blood fractionation products for use in transfusion. These war-related projects involved complex translations between basic and applied research, managed through close collaborations between scientists, government, and industry. The blood fractionation project, organized by Edwin Cohn of the physical chemistry department at Harvard, was one of the wartime successes that stimulated a massive expansion of public funding for basic biochemical research in postwar America.

One manifestation of this new focus was the foundation of institutes dedicated to basic biochemistry, the first being the Enzyme Institute at the University of Wisconsin, opened in 1950. By the 1960s, fundamental biochemical research was firmly entrenched institutionally, and American biochemists were making ever more inter-nationally renowned contributions to all areas of bio-chemistry. Indicative of this trend is the rapid increase in Nobel laureates among American biochemists.

Between 1901 and 1950, only three Nobel Prizes were awarded for American biochemical research: the 1946 chemistry prize awarded to James B. Sumner, John H. Northrop, and Wendell M. Stanley for work on enzymes and virus proteins; and two prizes in physiology or medicine (shared with others abroad), awarded to Edward A. Doisy in 1943 for work on vitamin K, and to Carl F. Cori and Gerty Radnitz Cori in 1947 for work on glycogen metabolism. (Gerty Cori was the third woman, and the first woman biochemist, to win a Nobel Prize.) In the second half of the twentieth century, by contrast, approximately forty Nobel Prizes were awarded for American research with a biochemical dimension, to some seventy American laureates.

In this later period, biochemistry became increasingly intertwined with molecular biology and cell biology, partly through the development of new chemical, physical, and morphological techniques used in all three fields and through much traffic of biochemists across the boundaries between them. For biochemistry, these new developments made it possible to locate particular biochemical reactions in specific structures of the cell. Moreover, its institutional strength and practical flexibility enabled bio-chemistry to withstand challenges to its status as a fundamental science of life when these were issued in the 1950s and 1960s by molecular biologists seeking autonomy for their own science. In practice, there has been continuous overlap, and in 1987 the American Society of Biological Chemists renamed itself the American Society for Biochemistry and Molecular Biology.

BIBLIOGRAPHY

Apple, Rima D. Vitamania: Vitamins in American Culture. New Brunswick: Rutgers University Press, 1996.

Bud, Robert. The Uses of Life: A History of Biotechnology. New York: Cambridge University Press, 1993.

De Chadarevian, Soraya, and Harmke Kamminga, eds. Molecularizing Biology and Medicine: New Practices and Alliances, 1910s–1970s. Amsterdam: Harwood Academic Publishers, 1998.

Kohler, Robert E. From Medical Chemistry to Biochemistry: The Making of a Biomedical Discipline. Cambridge, U.K.: Cambridge University Press, 1982.

HarmkeKamminga

See alsoChemistry ; Medical Research ; Microbiology ; Molecular Biology ; Nutrition and Vitamins .

Biochemistry

Biochemistry is the study of the molecular basis of life. The study of biochemistry includes the knowledge of the structure and function of molecules found in the biological world and an understanding of the precise biochemical pathways by which organic molecules are either put together or broken down.

Biochemistry seeks to describe the structure, organization, and functions of living matter in molecular terms. Essentially two factors have contributed to the excitement in the field today and have enhanced the impact of research and advances in biochemistry on other life sciences. Firstly, it is now generally accepted that the physical elements of living matter obey the same fundamental laws that govern all matter, both living and non-living. Therefore, the full potential of modern chemical and physical theory can be brought in to solve certain biological problems. Secondly, incredibly powerful new research techniques, notably those developing from the fields of biophysics and molecular biology , are permitting scientists to ask questions about the basic process of life.

Biochemistry draws on its major themes from many disciplines. For example from organic chemistry , which describes the properties of biomolecules; from biophysics, which applies the techniques of physics to study the structures of biomolecules; from medical research, which increasingly seeks to understand disease states in molecular terms and also from nutrition , microbiology, physiology , cell biology, and genetics .

Origins of and development of biochemistry

Biochemistry draws strength from all of these disciplines but is also a distinct discipline, with its own identity. It is distinctive in its emphasis on the structures and relations of biomolecules, particularly enzymes and biological catalysis; on the elucidation of metabolic pathways and their control; and on the principle that life processes can, at least on the physical level, be understood through the laws of chemistry. It has its origins as a distinct field of study in the early nineteenth century, with the pioneering work of Friedrich Wöhler. Prior to Wöhler's time it was believed that the substance of living matter was somehow quantitatively different from that of nonliving matter and did not behave according to the known laws of physics and chemistry. In 1828 Wöhler showed that urea , a substance of biological origin excreted by humans and many animals as a product of nitrogen metabolism, could be synthesized in the laboratory from the inorganic compound ammonium cyanate. As Wöhler phrased it in a letter to a colleague, "I must tell you that I can prepare urea without requiring a kidney or an animal , either man or dog." This was a shocking statement at the time, for it breached the presumed barrier between the living and the nonliving. Later, in 1897, two German brothers, Eduard and Hans Buchner, found that extracts from broken and thoroughly dead cells from yeast , could nevertheless carry out the entire process of fermentation of sugar into ethanol . This discovery opened the door to analysis of biochemical reactions and processes in vitro (Latin "in glass"), meaning in the test tube rather than in vivo, in living matter. In succeeding decades many other metabolic reactions and reaction pathways were reproduced in vitro, allowing identification of reactants and products and of enzymes, or biological catalysts, that promoted each biochemical reaction.

Until 1926, the structures of enzymes (or "ferments") were thought to be far too complex to be described in chemical terms. But in 1926 J.B. Sumner showed that the protein urease, an enzyme from jack beans, could be crystallized like other organic compounds. Although proteins have large and complex structures, they are also organic compounds and their physical structures can be determined by chemical methods.

Modern biochemistry

Today, the study of biochemistry can be broadly divided into three principal areas: (1) the structural chemistry of the components of living matter and the relationships of biological function to chemical structure; (2) metabolism, the totality of chemical reactions that occur in living matter; and (3) the chemistry of processes and substances that store and transmit biological information. The third area is also the province of molecular genetics, a field that seeks to understand heredity and the expression of genetic information in molecular terms.

Biochemistry is having a profound influence in the field of medicine. The molecular mechanisms of many diseases, such as sickle cell anemia and numerous errors of metabolism , have been elucidated. Assays of enzyme activity are today indispensable in clinical diagnosis . To cite just one example, liver disease is now routinely diagnosed and monitered by measurements of blood levels of enzymes called transaminases and of a hemoglobin breakdown product called bilirubin. Deoxyribonucleic acid (DNA) probes are coming into play in diagnosis of genetic disorders , infectious diseases, and cancers. Genetically engineered strains of bacteria containing recombinant DNA are producing valuable proteins such as insulin and growth hormone. Furthermore, biochemistry is a basis for the rational design of new drugs. Also the rapid development of powerful biochemical concepts and techniques in recent years has enabled investigators to tackle some of the most challenging and fundamental problems in medicine and physiology. For example in embryology , the mechanisms by which the fertilized embryo gives rise to cells as different as muscle, the brain and liver are being intensively investigated. Also, in anatomy , the question of how cells find each other in order to form a complex organ , such as the liver or brain, are being tackled in biochemical terms. The impact of biochemistry is being felt in so many areas of human life, through this kind of research and the discoveries are fuelling the growth of the life sciences as a whole.

The biochemistry of digestion, for example, includes the study of the pathways involving changes in molecular structure, and all enzyme interactions that take place when large food molecules (proteins, lipids, or carbohydrates) are broken down into smaller molecules capable of uptake and use by the cells of a living body.

Fundamental advances in biochemistry have also allowed important advances in genetics and molecular biology. The discovery of the composition—and subsequentely the double-helical structure—of DNA provided a critical and highly demonstrable link between biochemical form and function. The structure of the DNA molecule is remarkably well suited to its ability to make more copies of itself. The hydrogen bonds between the base pairs of the DNA double helix enable the two-stranded double helix molecule to unzip easily so that each piece can act as a pattern to build new DNA molecules.

Another area of interest to biochemists involves the flow of genetic information from DNA to RNA to protein is the same in all organisms. ATP (adenosine triphosphate ), which is the universal currency of energy in biological systems, is generated in similar ways by all forms of life. Furthermore, biochemists were able to unravel some of the central metabolic pathways and energy-conversion mechanisms. The determination of the three-dimensional structure and the mechanism of action of many protein molecules were also significant achievements in the field of biochemistry.

Identifying and sequencing genes responsible for causing diseases, and genetic cloning technology has led to remarkable progress in understanding the relationships of genes and proteins. In addition, the molecular bases of several diseases, such as sickle cell anemia , and numerous inborn errors of metabolism are now known. Biochemical assays for enzyme activities have become indispensable in clinical diagnosis.

Indeed, the field of biochemistry, which investigates the relationship between molecular structure and function of living things at a molecular level, has been profoundly transformed by recombinant DNA technology . This has led to the integration of molecular genetics and protein biochemistry. The intricate interplay of the genetic makeup (genotype) and how the molecular structure influences function and the various physical traits (phenotype) is now being unraveled at the molecular level.

See also Amino acid; Hormones; Photosynthesis.

Resources

books

Boyer, Rodney. Concepts in Biochemistry. Pacific Grove, CA: Brooks/Cole Publishing Company, 1999.

Jorde, L.B., J.C. Carey, M.J. Bamshad, and R.L. White. Medical Genetics, 2nd ed. St. Louis: Mosby-Year Book, Inc., 2000.

Lodish, H., et. al. Molecular Cell Biology, 4th ed. New York: W. H. Freeman & Co., 2000.

Nelson, David L., David L. Nelson, and Michael M. Cox. Lehninger Principles of Biochemistry, 3rd edition. Worth Publishing, 2000.

Judyth Sassoon

Biochemistry

Biochemistry seeks to describe the structure, organization, and functions of living matter in molecular terms. Essentially two factors have contributed to the excitement in the field today and have enhanced the impact of research and advances in biochemistry on other life sciences. First, it is now generally accepted that the physical elements of living matter obey the same fundamental laws that govern all matter, both living and non-living. Therefore the full potential of modern chemical and physical theory can be brought in to solve certain biological problems. Secondly, incredibly powerful new research techniques, notably those developing from the fields of biophysics and molecular biology , are permitting scientists to ask questions about the basic process of life that could not have been imagined even a few years ago.

Biochemistry now lies at the heart of a revolution in the biological sciences and it is nowhere better illustrated than in the remarkable number of Nobel Prizes in Chemistry or Medicine and Physiology that have been won by biochemists in recent years. A typical example is the award of the 1988 Nobel Prize for Medicine and Physiology, to Gertrude Elion and George Hitchings of the United States and Sir James Black of Great Britain for their leadership in inventing new drugs. Elion and Hitchings developed chemical analogs of nucleic acids and vitamins which are now being used to treat leukemia, bacterial infections, malaria , gout, herpes virus infections and AIDS . Black developed beta-blockers that are now used to reduce the risk of heart attack and to treat diseases such as asthma. These drugs were designed and not discovered through random organic synthesis. Developments in knowledge within certain key areas of biochemistry, such as protein structure and function, nucleic acid synthesis, enzyme mechanisms, receptors and metabolic control, vitamins, and coenzymes all contributed to enable such progress to be made.

Two more recent Nobel Prizes give further evidence for the breadth of the impact of biochemistry. In 1997, the Chemistry Prize was shared by three scientists: the American Paul Boyer and the British J. Walker for their discovery of the "rotary engine" that generates the energy-carrying compound ATP, and the Danish J. Skou, for his studies of the "pump" that drives sodium and potassium across membranes. In the same year, the Prize in Medicine and Physiology went to Stanley Prusiner , for his studies on the prion, the agent thought to be responsible for "mad cow disease" and several similar human conditions.

Biochemistry draws on its major themes from many disciplines. For example from organic chemistry, which describes the properties of biomolecules; from biophysics, which applies the techniques of physics to study the structures of biomolecules; from medical research, which increasingly seeks to understand disease states in molecular terms and also from nutrition, microbiology, physiology, cell biology and genetics. Biochemistry draws strength from all of these disciplines but is also a distinct discipline, with its own identity. It is distinctive in its emphasis on the structures and relations of biomolecules, particularly enzymes and biological catalysis, also on the elucidation of metabolic pathways and their control and on the principle that life processes can, at least on the physical level, be understood through the laws of chemistry. It has its origins as a distinct field of study in the early nineteenth century, with the pioneering work of Freidrich Wöhler. Prior to Wöhler's time it was believed that the substance of living matter was somehow quantitatively different from that of nonliving matter and did not behave according to the known laws of physics and chemistry. In 1828 Wöhler showed that urea, a substance of biological origin excreted by humans and many animals as a product of nitrogen metabolism , could be synthesized in the laboratory from the inorganic compound ammonium cyanate. As Wöhler phrased it in a letter to a colleague, "I must tell you that I can prepare urea without requiring a kidney or an animal, either man or dog." This was a shocking statement at the time, for it breached the presumed barrier between the living and the nonliving. Later, in 1897, two German brothers, Eduard and Hans Buchner, found that extracts from broken and thoroughly dead cells from yeast , could nevertheless carry out the entire process of fermentation of sugar into ethanol. This discovery opened the door to analysis of biochemical reactions and processes in vitro (Latin "in glass"), meaning in the test tube rather than in vivo, in living matter. In succeeding decades many other metabolic reactions and reaction pathways were reproduced in vitro, allowing identification of reactants and products and of enzymes, or biological catalysts, that promoted each biochemical reaction.

Until 1926, the structures of enzymes (or "ferments") were thought to be far too complex to be described in chemical terms. But in 1926, J.B. Sumner showed that the protein urease, an enzyme from jack beans, could be crystallized like other organic compounds. Although proteins have large and complex structures, they are also organic compounds and their physical structures can be determined by chemical methods.

Today, the study of biochemistry can be broadly divided into three principal areas: (1) the structural chemistry of the components of living matter and the relationships of biological function to chemical structure; (2) metabolism, the totality of chemical reactions that occur in living matter; and (3) the chemistry of processes and substances that store and transmit biological information. The third area is also the province of molecular genetics , a field that seeks to understand heredity and the expression of genetic information in molecular terms.

Biochemistry is having a profound influence in the field of medicine. The molecular mechanisms of many diseases, such as sickle cell anemia and numerous errors of metabolism, have been elucidated. Assays of enzyme activity are today indispensable in clinical diagnosis. To cite just one example, liver disease is now routinely diagnosed and monitored by measurements of blood levels of enzymes called transaminases and of a hemoglobin breakdown product called bilirubin. DNA probes are coming into play in diagnosis of genetic disorders, infectious diseases and cancers. Genetically engineered strains of bacteria containing recombinant DNA are producing valuable proteins such as insulin and growth hormone. Furthermore, biochemistry is a basis for the rational design of new drugs. Also the rapid development of powerful biochemical concepts and techniques in recent years has enabled investigators to tackle some of the most challenging and fundamental problems in medicine and physiology. For example in embryology, the mechanisms by which the fertilized embryo gives rise to cells as different as muscle, brain and liver are being intensively investigated. Also, in anatomy, the question of how cells find each other in order to form a complex organ, such as the liver or brain, are being tackled in biochemical terms. The impact of biochemistry is being felt in many areas of human life through this kind of research, and the discoveries are fuelling the growth of the life sciences as a whole.

See also Antibody-antigen, biochemical and molecular reactions; Biochemical analysis techniques; Biogeochemical cycles; Bioremediation; Biotechnology; Immunochemistry; Immunological analysis techniques; Miller-Urey experiment; Nitrogen cycle in microorganisms; Photosynthesis

Biochemistry

Origins of and development of biochemistry

Modern biochemistry

Resources

Biochemistry is the study of the molecular chemical basis of life. The study of biochemistry includes the knowledge of the structure and function of molecules found in the biological world and an understanding of the precise biochemical pathways by which organic molecules are either put together or broken down. Biochemistry seeks to describe the structure, organization, and functions of living matter in molecular terms.

The physical elements of living matter obey the same fundamental laws that govern all living and non-living matter. Therefore, the full potential of modern chemical and physical theory can be brought in to solve certain biological problems. Additionally, biophysics and molecular biology techniques are permitting scientists to ask questions about the basic process of life.

Biochemistry draws on its major themes from many disciplines. For example from organic chemistry, which describes the properties of biomolecules; from biophysics, which applies the techniques of physics to study the structures of biomolecules; from medical research, which increasingly seeks to understand disease states in molecular terms and also from nutrition, microbiology, physiology, cellbiology and genetics.

Origins of and development of biochemistry

Biochemistry draws strength from all of these disciplines but is also a distinct discipline, with its own identity. It is distinctive in its emphasis on the structures and relations of biomolecules, particularly enzymes and biological catalysis on the elucidation of metabolic pathways and their control and on the principle that life processes can, at least on the physical level, be understood through the laws of chemistry. It has its origins as a distinct field of study in the early nineteenth century, with the pioneering work of Friedrich Wöhler (1800–1882). Prior to Wöhler’s time it was believed that the substance of living matter was somehow quantitatively different from that of nonliving matter and did not behave according to the known laws of physics and chemistry.

In 1828 Wöhler showed that urea, a substance of biological origin excreted by humans and many animals as a product of nitrogen metabolism, could be synthesized in the laboratory from the inorganic compound ammonium cyanate. Later, in 1897, two German brothers, Eduard and Hans Buchner, found that extracts from broken and thoroughly dead cells from yeast, could nevertheless carry out the entire process of fermentation of sugar into ethanol. This discovery opened the door to analysis of biochemical reactions and processes in vitro (Latin “in glass”), meaning in the test tube rather than in vivo (in living matter). In succeeding decades many other metabolic reactions and reaction pathways were reproduced in vitro, allowing identification of reactants and products and of enzymes, or biological catalysts, that promoted each biochemical reaction.

Until 1926, the structures of enzymes (or “ferments”) were thought to be far too complex to be described in chemical terms. But in 1926 J.B. Sumner showed that the protein urease, an enzyme from jack beans, could be crystallized like other organic compounds. Although proteins have large and complex structures, they are also organic compounds and their physical structures can be determined by chemical methods.

Modern biochemistry

Today, the study of biochemistry can be broadly divided into three principal areas: (1) the structural chemistry of the components of living matter and the relationships of biological function to chemical structure; (2) metabolism, the total chemical reactions that occur in living matter; and (3) the chemistry of processes and substances that store and transmit biological information. The third area is also the province of molecular genetics, a field that seeks to understand heredity and the expression of genetic information in molecular terms.

Biochemistry is having a profound influence in the field of medicine. The molecular mechanisms of many diseases, such as sickle cell anemia and numerous errors of metabolism, have been elucidated. Assays of enzyme activity are today indispensable in clinical diagnosis. For example, liver disease is routinely diagnosed and monitored by measurements of blood levels of enzymes called transaminases and of a hemoglobin breakdown product called bilirubin. Deoxyribonucleic acid (DNA) probes enable the detection of some genetic disorders, infectious diseases, and cancers. Genetically engineered strains of bacteria containing recombinant DNA are producing valuable proteins such as human insulin and growth hormone. Biochemistry is also a fundamentally important part of drug design.

Identifying and sequencing genes responsible for causing diseases, and genetic cloning technology has led to remarkable progress in understanding the relationships of genes and proteins. In addition, the molecular bases of several diseases, such as sickle cell anemia, and numerous inborn errors of metabolism are now known. Biochemical assays for enzyme activities have become indispensable in clinical diagnosis. Indeed, the field of biochemistry, which investigates the relationship between molecular structure and function of living things at a molecular level, has been profoundly transformed by recombinant DNA technology. This has led to the integration of molecular genetics and protein biochemistry. The intricate interplay of the genetic make-up (genotype) and how the molecular structure influences function and the various physical traits (phenotype) is being unraveled at the molecular level.

Resources

BOOKS

Berg, Jermey M., John L. Tymoczko, and Lubert Stryer. Biochemistry. New York: W.H. Freeman, 2006.

Nelson, David L. and Michael M. Cox. Lehninger Principles of Biochemistry, Fourth Edition. New York: W.H. Freeman, 2004.

Voet, Donald and Judith G. Voet. Biochemistry. New York: John Wiley & Sons, 2006.

Judyth Sassoon

biochemistry The science of biochemistry, nowadays regarded as one of the fundamental pillars upon which the study of medicine rests, is something of a newcomer. It has its origins almost equally in chemistry and physiology, and indeed what we would today call biochemistry was commonly referred to as physiological chemistry a hundred years ago. Looking further back we can trace early ideas about the make-up of living things to the birth of organic chemistry, the scope of which seems originally to have been a good deal wider than would be admitted today. In 1806 Berzelius referred to organic chemistry as ‘the part of physiology which describes the composition of living bodies, and the chemical processes which occur in them. In the early nineteenth century there was a good deal of debate as to whether the chemical substances found in living things were fundamentally different in character from the ‘inorganic’ constituents of inanimate matter, and the issue was only resolved (in favour of no difference) with the chemical synthesis of urea by Wöhler in 1828 and by subsequent syntheses of molecules hitherto only associated with living organisms. Thereafter organic chemistry became confined to the study of carbon compounds, and knowledge of the transformations undergone by such compounds in the course of metabolism was left to be re-born as biochemistry decades later. A major influence in that re-birth was the concept of catalysis and the realization that catalysts must play a vital part in living processes. Here the studies of Pasteur and his contemporaries in the mid nineteenth century played an indispensable part, and led to the broad unifying concept that the nature of life processes must be very similar in disparate organisms, including man, and that catalytic enzymes (the word literally means ‘in yeast’) are responsible for directing and controlling chemical transformations in the living cell.

Given the acceptance of the concept of oxidation, and the demise of the phlogiston theory, thanks to the work of Lavoisier in the late 1700s, it was natural that the early study of metabolism should be preoccupied with understanding the processes of respiration, breakdown of sugars, and energy generation. There was also much interest in nutrition and the chemical processes underlying the digestion of food. The identification of enzymes as proteins arose naturally from these efforts and spawned the science of enzymology, which remains a major division of biochemistry to the present day. The question of how enzymes work engaged the attention of many of the finest biochemical brains in the 1990s and will continue to do so for the foreseeable future. Moreover, the day is not far away when enzymologists will astonish us all by creating more or less de novo enzymes endowed with hitherto-unknown catalytic properties. Already ‘catalytic antibodies’ have been described, that bind small molecules with exquisite specificity, producing chemical change, and as knowledge of fundamental mechanisms of catalysis emerges from the efforts of physical organic chemists, the practical applications of that knowledge will not be far behind.

It was with the arrival of the twentieth century that biochemistry came of age, so to speak, and made such a major impact on medicine that it was recognized as a formidable science indispensable to the understanding of the human body. Those were the days of vitamin and hormone research. The pioneering work of Sir Frederick Gowland Hopkins (1861–1947) and his colleagues, which led to the discovery of vitamins, had a lasting influence on generations of biochemists and underpinned the unravelling of intermediary metabolism. The isolation, identification, and eventual production of hormones in sufficient quantity for therapeutic use likewise illuminated some of the most perplexing medical problems, and transformed endocrinology into an important branch of clinical science.

Biochemistry has long boasted of its roots in exact physical sciences and has never been afraid to divert the attentions of practitioners of those sciences to the study of life. By that route some of the most spectacular advances of knowledge in the twentieth century have been achieved, perhaps none more so than the birth of the enfant terrible, molecular biology, which nowadays dominates the subject. Molecular biology, rooted in structural studies on proteins and nucleic acids, owes much to the contributions of far-sighted crystallographers and geneticists (aided and abetted by a cohort of physicists and even mathematicians) who built upon the bed-rock of biochemistry to produce a veritable revolution in biology that is still evolving apace. It is sometimes hard to imagine how abstract the concept of a gene was prior to the discovery of the structure of DNA by Watson and Crick in 1953, since nowadays the precise identification of genes and expectations of their manipulation (for good or ill) can be read about in newspapers intended for the man in the street. Biochemistry is no longer the academic tool of medical researchers but, having embraced its sister disciplines in the physical as well as biological sciences, has taken on new meaning as the huge promise of biotechnology looms before us.

Never has it been more evident how the pace of scientific discovery is driven by technical advances in experimentation, the invention of new techniques, and the application of ideas imported from cognate disciplines. The twin sciences of molecular and cell biology have adapted the foundations laid by the painstaking ‘bucket’ experiments of the early biochemists to illuminate the marvels and mysteries of molecules and cells in a fashion which can only be described as spectacular. Even philosophers and theologians can no longer ignore the prospects of bio-revolution introduced into our daily lives: genetically engineered foodstuffs; super-athletes; new approaches to treating infertility; eradication of diseases. How many more triumphs (or horrors) attributable to the application of biochemically-based technology await us? And how are we going to cope with them?

M. J. Waring