Figure 1.1: a - DNA double helix section; b - Schematic representation of a single (coding) strand of DNA

Figure 1.1 a: DNA double helix section DNA consists of a sugar molecule (deoxyribose), a phosphate group and combinations of the four nitrogenous bases, adenine (A), thymine (T), cytosine (C) and guanine (G). The sugar and phosphate groups form the backbone of the molecule, while the nitrogenous bases interact to form base pairs. The interaction between base pairs occurs through hydrogen bonding. Hydrogen bonds are weak bonds which result from electrostatic interaction between positively charged and negatively charged molecules.

Figure 1.1 b: Schematic representation of a single (coding) strand of DNA The order of the bases along the length of the DNA constitutes the genetic code and gives the instructions from which proteins are made. Each set of three bases, or codon, specifies a particular amino acid. Amino acids are the building blocks of proteins.

Figure 1.1: Top: a - DNA double helix section; Bottom: b - Schematic representation of a single (coding) strand of DNA

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