Genetic Engineering

Fst 01 Topic Discussion on Genetic Engineering by Student Help.

1. Genetic Engineering

·        Need.  To produce large quantities of scarce biologically significant proteins which are not easily available from natural sources.

·        How ? The modern Biotechnology revolution is based on understanding and manipulation of the structure of D.N.A

·        What is D.N.A?

·        D.N.A is a complex organic molecule that directs the synthesis of proteins in all living beings.

·        Controls physical structure,growth,reproduction, function of all living beings.

·        The programme for controlling protein synthesis is coded in the chemical structure of DNA.

·        The foundation of genetic engineering was laid by the discovery, that DNA supplied from outside is accepted by micro-organisms.

·        DNA thus inserted into the cell from a micro-organism, enables the cells to make the proteins specified in the codes of the inserted DNA.

·        These new cells can be cultivated or cloned, until a significant number of cells are available  to produce specific, desired protein molecules.

·        However, this is not so easily done.

·        When a foreign DNA molecule enters a cell, special enzymes, called restriction enzymes, rapidly destroy it.

·        This problem was solved by the discovery of the fact that small rings of DNA other than the main DNA strands exist in the cells of bacteria.

·        These circular DNA molecules are called plasmids.

·        A technique was developed to insert foreign DNA fragments into plasmids taken out of the cells.

·        This is known as gene splicing and plasmid becomes a vehicle or a vector.

·        Once the foreign DNA is joined to the plasmids, and inserted back in the host cell, the restriction enzymes fail to destroy it.

·        When the cell reproduces, the foreign DNA is also replicated.

·        When the cell carries on its normal functions, the synthetic DNA in the plasmid directs the manufacture of the protein coded in it.

·        USES / ADVANTAGES Thus, through genetic engineering techniques, it is possible to introduce a foreign DNA into a host cell and synthesize any desired protein.

·        Large quantities of scarce biologically significant proteins which are not easily available from natural sources can be manufactured in this manner.

·        For example, insulin needed by diabetic patients can now be produced on a large scale using this technique.

·       

·        Just as cattle are bred for specific functions like high milk yield, or pulling heavy loads, now-a-days scientists breed bacteria for carrying out special functions.

·        By selecting suitable bacteria, and using genetic engineering techniques, new variety of bacteria which can eat man-made artificial products like plastics are being developed. Otherwise plastic materials, discarded and thrown in garbage, are hard to get rid off.

·        These special bacteria are affectionately called 'Bugs'.