Biochemistry

Biochemistry
As understanding of inanimate chemistry
grew during the 19th century, attempts to
interpret the physiological processes of
living organisms in terms of molecular
structure and reactivity gave rise to the
discipline of biochemistry. Biochemists
employ the techniques and theories of
chemistry to probe the molecular basis of
life. An organism is investigated on the
premise that its physiological processes
are the consequence of many thousands of
chemical reactions occurring in a highly
integrated manner. Biochemists have
established, among other things, the
principles that underlie energy transfer in
cells, the chemical structure of cell
membranes, the coding and transmission
of hereditary information, muscular and
nerve function, and biosynthetic pathways.
In fact, related biomolecules have been
found to fulfill similar roles in organisms as
different as bacteria and human beings. The
study of biomolecules, however, presents
many difficulties. Such molecules are often
very large and exhibit great structural
complexity; moreover, the chemical
reactions they undergo are usually
exceedingly fast. The separation of the two
strands of DNA, for instance, occurs in one-
millionth of a second. Such rapid rates of
reaction are possible only through the
intermediary action of biomolecules called
enzymes. Enzymes are proteins that owe
their remarkable rate-accelerating abilities
to their three-dimensional chemical
structure. Not surprisingly, biochemical
discoveries have had a great impact on the
understanding and treatment of disease.
Many ailments due to inborn errors of
metabolism have been traced to specific
genetic defects. Other diseases result from
disruptions in normal biochemical
pathways.
Frequently, symptoms can be alleviated by
drugs, and the discovery, mode of action,
and degradation of therapeutic agents is
another of the major areas of study in
biochemistry. Bacterial infections can be
treated with sulfonamides, penicillins, and
tetracyclines, and research into viral
infections has revealed the effectiveness of
acyclovir against the herpes virus. There is
much current interest in the details of
carcinogenesis and cancer chemotherapy. It
is known, for example, that cancer can
result when cancer-causing molecules, or
carcinogens as they are called, react with
nucleic acids and proteins and interfere
with their normal modes of action.
Researchers have developed tests that can
identify molecules likelyto be carcinogenic.
The hope, of course, is that progress in the
prevention and treatment of cancer will
accelerate once the biochemical basis of
the disease is more fully understood.
The molecular basis of biologic processes
is an essential feature of the fast-growing
disciplines of molecular biology and
biotechnology. Chemistry has developed
methods for rapidly and accurately
determining the structure of proteins and
DNA. In addition, efficient laboratory
methods for the synthesis of genes are
being devised. Ultimately, the correction of
genetic diseases by replacement of
defective genes with normal ones may
become possible.