3.16 DNA and Genetic Information

3:16 Describe a DNA molecule as two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with thymine (T), and cytosine (C) with guanine (G)

Chromosomes are likely to contain thousands of genes
Each gene contains a double helix (that is a pair of Helices that appear to be parallel to one another)

The Helices are known as the sugar-phosphate backbone
In the centre of these Helices there are four types of bases, known as adenine, thymine, cytosine and guanine. These bases are holding together the two helices. They are hold together by pairing up the four bases; A with T & C with G, these are known as the base pairs and are always found in DNA.

The order of these base pairs defines the gene. For example take the order of the bases shown on the right of below image: AGTGAACCAG. This order is called the Gene, so by changing the order, you theoretically change the gene.

We can therefore define a gene as being a combination of the order of the bases (ATGC) and the number of bases on one side of the helix. And this code somehow constructs specific proteins in the cytoplasm that somehow gives us the characteristics.