Biotechnology

Biotechnology is the application of biological processes in the development of products. These products may be organisms, cells, parts of a cell, or chemicals for use in medicine, biology, or industry.

History of biotechnology

Biotechnology has been used by humans for thousands of years in the production of beer and wine. In a process called fermentation, microorganisms such as yeasts and bacteria are mixed with natural products that the microorganisms use as food. In winemaking, yeasts live on the sugars found in grape juice. They digest these sugars and produce two new products: alcohol and carbon dioxide.

Early in the twentieth century, scientists used bacteria to break down, or decompose, organic matter in sewage, thus providing a means for dealing efficiently with these materials in solid waste. Microorganisms were also used to produce various substances in the laboratory.

Hybridization

Hybridization—the production of offspring from two animals or plants of different breeds, varieties, or species—is a form of biotechnology that does not depend on microorganisms. Farmers long ago learned that they could produce offspring with certain characteristics by carefully selecting the parents. In some cases, entirely new animal forms were created that do not occur in nature. An example is the mule, a hybrid of a horse and a donkey.

Hybridization has also been used for centuries in agriculture. Most of the fruits and vegetables in our diet today have been changed by long decades of plant crossbreeding. Modern methods of hybridization have contributed to the production of new food crops and resulted in a dramatic increase in food production.

Discovery of DNA leads to genetic engineering

The discovery of the role of deoxyribonucleic acid (DNA) in living organisms greatly changed the nature of biotechnology in the second half of the twentieth century. DNA, located in the nucleus of cells, is a complex molecule that stores and transmits genetic information. This information provides cells with the directions to carry out vital bodily functions.

With the knowledge of how genetic information is stored and transmitted, scientists have developed the ability to alter DNA, creating new instructions that direct cells to produce new substances or perform new functions. The process of DNA alteration is known as genetic engineering. Genetic engineering often involves combining the DNA from two different organisms, a technique referred to as recombinant DNA research.

There is little doubt that genetic engineering is the best known form of biotechnology today, with animal cloning and the Human Genome Project making headlines in the news. Indeed, it is easy to confuse the two terms. However, they differ in the respect that genetic engineering is only one type of biotechnology.

Monoclonal antibodies

Another development in biotechnology is the discovery of monoclonal antibodies. Monoclonal antibodies are antibodies produced in the laboratory by a single cell. The single cell is formed by the union of two other cells—a cancer cell and an animal cell that makes a particular antibody. The hybrid cell multiplies rapidly, making clones of itself and

An animal cell being microinjected with foreign genetic material. (Reproduced by permission of

Photo Researchers, Inc.

)

producing large quantities of the antibody. (Antibodies are chemicals produced in the body that fight against foreign substances, such as bacteria and viruses.) Monoclonal antibodies are used in research, medical testing, and for the treatment of specific diseases.

[ See also Clone and cloning ; Endangered species ; Fermentation ; Genetic engineering ; Human Genome Project ; Nucleic acid ]