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Describe, Using Diagrams, the Structure of Dna.
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Describe, using diagrams, the structure of DNA. 5 Marks DNA is the acronym for Deoxyribose Nucleic Acid. DNA is a macromolecule. This is because DNA is a polymer. This means that it is made up of many repeating sub-units. These sub units are called nucleotides. Nucleotides are made of three components. These are: * A nitrogen containing base * A pentose sugar * A phosphate group These three components are assembled in the following way: The phosphate group of the nucleotide joins with the sugar group of another nucleotide. This forms a phospho-sugar backbone. DNA is made up of two polynucleotides that lie side by side in opposite directions. The two polynucleotides are held together by hydrogen bonds between the bases. The following diagram shows how this is done. The purine bases are larger than the pyrimidine bases. In a DNA molecule there is just enough space between the two phospho-sugar backbones for one purine and one pyrimidine...
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