Divisions of biotechnology

Biotechnology is often used to refer to genetic engineering technology of the 21^st century, however the term encompasses a wider range and history of procedures for modifying biological organisms according to the needs of humanity, going back to the initial modifications of native plants into improved food crops through artificial selection and hybridization. Bioengineering is the science upon which all Biotechnological applications are based. With the development of new approaches and modern techniques, traditional biotechnology industries are also acquiring new horizons enabling them to improve the quality of their products and increase the productivity of their systems.

Before 1971, the term, biotechnology, was primarily used in the food processing and agriculture industries. Since the 1970s, it began to be used by the Western scientific establishment to refer to laboratory-based techniques being developed in biological research, such as recombinant DNA or tissue culture-based processes, or horizontal gene transfer in living plants, using vectors such as the Agrobacteriurnbacteria to transfer DNA into a host organism. In fact, the term should be used in a much broader sense to describe the whole range of methods, both ancient and modern, used to manipulate organic materials to reach the demands of food production. So the term could be defined as, "The application of indigenous and/or scientific knowledge to the management of (parts of) microorganisms, or of cells and tissues of higher organisms, so that these supply goods and services of use to the food industry and its consumers.

Biotechnology combines disciplines like genetics, molecular biology, biochemistry, embryology and cell biology, which are in turn linked to practical disciplines like chemical engineering, information technology, and robotics. Patho-biotechnology describes the exploitation of pathogens or pathogen derived compounds for beneficial effect.

Elements

We meet the idea of an element very early in our study of chemisty. The ancients suspected that there must be some very simple substances from which more complicated ones were built. At one time they thought that everything might be made up of earth, air and water; these got the name "element" which comes from the same word as "elementary" or simple.

This idea, though wrong, is still rather important one. The first man to recognise the modern type of element was Robert Boyle in the middle of seventeenth centure. His idea was that an element was just something which could not be broken down chemically into anything simpler. He knew of metals like iron, copper, tin, leadgold and silver and non-metals like carbon and sulphur, all the gases being called "air".

All pure metals are elements, but alloys such as brass, and solder are made from more than one metal. In many cases they may be regarded as a solution of one metal in the other, e.g. a lead/tin alloy can be made by dissolving tin in a molten lead. On the other hand, comparatively few of the elements are non-metals, and many of these are gases.

You may ask: What is the difference between a metal and a non-metal? This is a difficult question to answer, especially as you have not yet met many of the elements. Most metals are hard and have charactaristic luster (i.e. they can be highly polished), but some non-metals are dense, some are sufficiently light to float on water. So we cannot always judge by appearance and other simple properties alone. Most metals but not all, are good conductors of heat and electricity_, but some forma of the nonmetal carbon will also conduct electricity. If a metal is burnt in oxygen it produces a basic oxide, which - if soluble, in water - turns litmus blue. On the other hand, a non-metal when burnt in oxygen produces an acidic oxide. If this is soluble in water it forms an acid capable of turning litmus red.