FSc Part I || Chapter 02 || Nucleic Acids (DNA & RNA) explained in Urdu/Hindi скачать в хорошем качестве

FSc Part I || Chapter 02 || Nucleic Acids (DNA & RNA) explained in Urdu/Hindi

Nucleic acids were first isolated in 1869 by F. Miescher, from the nuclei of pus cells. Due to their isolation from nuclei and their acidic nature, they were named nucleic acids. Nucleic acids are of two types, deoxyribonucleic acid or DNA and ribonucleic acid or RNA. DNA occurs in chromosomes, in the nuclei of the cells and in much lesser amounts in mitochondria and chloroplasts. RNA is present in the nucleolus, in the ribosomes, in the cytosol and in smaller amounts in other parts of the cell. Nucleic acids are complex substances. They are polymers of units called nucleotides. DNA is made up of deoxyribonucleotides, while RNA is composed of ribonucleotides. Composition of Nucleotide Each nucleotide is made of three subunits, a 5-carbon monosaccharide (a) pentose sugar), a nitrogen containing base, and a phosphoric acid. Pentose sugar in ribonucleotide is ribose, while in deoxyribonucleotide it is deoxyribose. Nitrogenous bases are of two types, single-ringed pyrimidines, and double-ringed purines. Pyrimidines are cytosine (abbreviated as C), thymine (abbreviated as T), and uracil (abbreviated as U). Purines are adenine (abbreviated as A) and guanine (abbreviated as G). Phosphoric acid (H₂PO4) has the ability to develop ester linkage with OH group of pentose sugar. In a typical nucleotide the nitrogenous base is attached to position 1 of pentose sugar, while phosphoric acid is attached to carbon at position 5 of pentose sugar. #Nucleic_acids #DNA #RNA #Nucleotide #Nucleoside #Ester_linkage