... of two nucleotides, a dinucleotide is formed. Continued condensation reactions lead to the formation of a polynucleotide. DNA is a double stranded polymer made up of two polynucleotide chains, where the pentose sugar is always deoxyribose and the organic bases are adenine, guanine, cytosine and thymine, but never uracil. The amount of guanine is usually equal to that of cytosine and the amount of adenine is usually equal to that of thymine. Its in the form of a helix whose shape is maintained by hydrogen bonds. Each chain has a sugar phosphate backbone on the outside with organic bases on the inside. The two chains are held together by complementary base pairing and are antiparallel. DNA has a very large molecular mass and is always found in the nucleus. There are three types of RNA that are involved in protein synthesis. These are mRNA, rRNA and tRNA. All three types ...

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