How are Genes and DNA organised?

DNA

DNA stands for deoxyribose nucleic acid. It is a stable, double stranded helix structured molecule which encodes all of our genetic information. It consists of a sugar-phosphate backbone, held together by specific nucleootide pairs. The entire DNA content of an organism is described as the genome. Using an analogy of a library, the genome is the entire library.

Nucleotides

If the genome is the library, individual nucleotides are the letters on the pages of the books. There are 4 nucletide bases, Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). When translated to RNA, Thymine becomes Uracil (U). These nucleotidea can be organised in various different orders.

Amino Acids

3 nucleotides encodes 1 amino acid. For example, if the genetic code read TCT, this would produce a Serine amino acid. An amino acid is the building block of a protein. Amino acids are like the chapters in a book, as the nucleotdies are organised into these different sections.

Genes

A sequence of amino acids will encode a gene. A gene can be thought of as the book which contains the chapters and letter. Each gene has a specific function. For exaple a specific gene for eye colour and there are hundreds of genes in our genome.

Chromosomes

Each gene has a specific position in the genome, known as a loci. This can be thought of as a specific position on a book shelf. The book shelves that books are packaged on to are the chromosomes. These are long, linear, X shaped structures which genes are packaged onto to jeep them stable within a cell.