Nucleic Acids,Watson and Crick,Pyrimidine,Purine,Pyrimidine,Cytosine,Guanine,Thymine,Genetic Information,Nucleotides,Triplet

Nucleic Acids

	Nucleic Acids It would be helpful to briefly describe some basics of molecular biology before attempting to understand its implications in biotechnology. The classical discovery of the structure of genetic material by Watson and Crick in 1953 revealed the unique suitability of nucleic acids for carrying genetic information and transmitting to subsequent generations. All the information needed for growth and multiplication of most organisms is carried by nucleic acids, especially the double-stranded deoxyribonucleic acid (DNA) or single or double stranded ribonucleic acid (RNA).
RNA differs from DNA in that the single strands have a ribose instead of deoxyribose and uracil in place of thymine. The double stranded DNA occurs in a helical structure with a backbone of alternating phosphate and deoxyribose molecules having a purine or a pyrimidine base linked to the I-position of each sugar molecule. The two complementary strands of DNA are twined together by hydrogen bonds between the purine and pyrimidine base pairs: adenine-thymine (AT) and guanine and cytosine (CT). An adenine in one strand of DNA occurs directly across a thymine in the other strand. Similarly, a guanine (G) occurring in one strand is bonded to a cytosine (q across the other strand).
The genetic information is coded by the linear arrangement of bases on the DNA strands. The sequence of nuc1eotides dictates all the characteristics of an organism and serves as a genetic code. The sequence of nulceotides, read in groups of three (triplet) reflects the sequence of amino acids in the large number of proteins (enzymes) synthesised by a cell. Each triplet is known as a codon and there are 64 possible combinations beginning with four nucleotides.

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Nucleic Acids