3. SYNOPSIS 1.Introduction. 2.One gene - 0ne enzyme concept. 3.Cistrons,mutons and recons. 4.Genetic code and characteristics. 5.Central dogma of molecular biology. 6.Transcription and translation. 7.Regulation of gene expression and lac-operon theory of regulation. Monday, May 9, 2011
4. The term gene was coined by Johannsen(1909). He defined gene as an elementary unit of inheritance.Morgan(1910) defined gene to be a part of chromosome which functions as unit of recombination. Gene is therefore, a unit of inheritance which carries coded information associated with a specific function. Monday, May 9, 2011
5. Characteristics. 1.It is a component of genetic material which contains coded information. 2.It is able to express its effect by regulating metabolism. 3.It is capable of replication. 4.It can undergo mutation. It is basic to biological variations that are essential for adaptation and evolution. 5.New genes develop due to reshuffling of components of existing genes. 6.It occupies a specific locus over the chromosome. Monday, May 9, 2011
6. Genes and Enzymes Archibald Garrod (father of biochemical genetics) found that black urine disease alkaptonuria is a genetic disorder caused by a recessive allele. The disorder is a result of an inborn error of metabolism wherein homogentisic acid or alkapton accumulates in the body.The acid is formed during metabolism of 2 amino acids,phenylalanine and tyrosine.Normally, alkapton or homogentisic acid is oxidized to CO2 and H2O with the help of alkapton oxidase. Phenylalanine +Tyrosine / Alkapton / oxidase CO2 +H2O Monday, May 9, 2011
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11. Codons of Genetic Code and Their Assignments U C A G UUU UCU UAU UGU U U UUC UCC UAC UGC C UUA UCA UAA UGA A UUG UCG UAG UGG G CUU CCU CAU CGU U C CUC CCC CAC CGC C CUA CCA CAA CGA A CUG CCG CAG CGG G A AUU ACU AAU AGU U AUC ACC AAC AGC C AUA ACA AAA AGA A AUG ACG AAG AGG G G GUU GCU GAU GGU U GUC GCC GAC GGC C GUA GCA GAA GGA A GUG GCG GAG GGG G