Tuesday, July 28, 2020

Biotechnology: Principles and Processes- Notes | Class 12 | Part 1: Principles of Biotechnology


· Biotechnology is the technique of using live organisms or their enzymes for products & processes useful to humans.

·  The European Federation of Biotechnology (EFB) defines Biotechnology as ‘the integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services’.

Biotechnology deals with:

-    Microbe-mediated processes (making curd, bread, wine etc).
-    In vitro fertilization (test-tube baby programme).
-    Synthesis and using of a gene.
-    Preparation of DNA vaccine.
-    Correcting a defective gene.


Core techniques of modern biotechnology

·   Genetic engineering: The technique in which genetic material (DNA & RNA) is chemically altered and introduced into host organisms to change the phenotype.

·  Bioprocess engineering: Maintenance of sterile ambience in chemical engineering processes for growing desired microbe/eukaryotic cell for the manufacture of antibiotics, vaccines, enzymes etc.

Basic steps in genetically modifying an organism

a)  Identification of DNA with desirable genes: Traditional hybridisation leads to inclusion and multiplication of undesirable genes along with desired genes. In genetic engineering, only desirable genes are introduced.

b)   Introduction of the identified DNA into the host: A vector DNA such as plasmid is used to deliver an alien piece of DNA into the host organism.

c)   Maintenance of introduced DNA in the host and transfer of the DNA to its progeny: A piece of alien DNA has no the sequence called Origin of replication (ori) needed for starting replication. So, it cannot multiply itself in the progeny cells of the organism. Hence alien DNA is integrated into the recipient genome (it has ori). It multiplies & inherits along with host DNA.

·  The process of joining and inserting a foreign piece of DNA into a host organism to produce new genetic combinations is called recombinant DNA technology.
·      First recombinant DNA (rDNA) was produced by Stanley Cohen & Herbert Boyer (1972).
·    They isolated an antibiotic resistance gene (piece of DNA) from a plasmid of Salmonella typhimurium. It was linked with a plasmid vector and transferred into E. coli. As a result, the gene was expressed & multiplied in E. coli.

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