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Showing posts from October, 2021

DNA - Basic structure

  Parts of DNA Phosphate group + sugar + Base (nitrogenous base) Difference between sugar of DNA and RNA DNA has deoxyribose sugar(1 OH group attached to sugar and RNA has ribose sugar (2 OH groups) Nucleotide and nucleoside Nucleotide = Phosphate group + Base + sugar Nucleoside = Base and sugar Types of Nitrogenous base Purines and Pyrimidines Purines consists of Pure As Gold = Adenine and Guanine Pyrimidine consists of CUT the pyramids Cytosine Uracil (only in RNA) Thymine Purine nucleosides are Adenosine and Guanosine Pyrimidine nucleosides are Cytidine, Uridine and Thymidine Purine nucleotides Adenosine monophosphate, Guanosine MP How is DNA packed inside nucleus ? In the form of chromatin which is further condensed to form chromosomes What is a nucleosome ? DNA coiled twice around an octamer of Histone composed of (H2A, H2B, H3, H4) x2 with linker H1 protein. Positive and Negative charge of Chromatin Positive charged =  Lysine  and  Arginine  of Histone which bind to negative char