DNA Structure

• DNA (deoxyribonucleic acid) is the molecule that contains genetic information of all orgasnisms.
• DNA is a polymer: the individual subunits of DNA are called nucleotides.
• Each nucleotide consists of a common sugar and phosphate group with one of 4 different bases attached to the sugar.
• There are 4 different nucleotides, each containing the same phosphate group and sugar but with a different base attached.
• The 4 different bases are called: Adenine (A), Thymine (T), Cytosine (C) and Guanine (G).
• Base pairing: Adenine always pairs with thymine (A-T) and cytosine always pairs with guanine (C-G). The bases on each strand pair up with each other, holding the two strands of DNA in the double helix.
• DNA strands have a backbone made of alternating sugars and phosphates.