How are Genes and DNA organised?

  • Google+ icon
  • LinkedIn icon
  • 716 views

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.

Emma S. GCSE Biology tutor, A Level Biology tutor, GCSE Chemistry tut...

About the author

is an online A Level Biology tutor with MyTutor studying at Newcastle University

Still stuck? Get one-to-one help from a personally interviewed subject specialist.

95% of our customers rate us

Browse tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok