A Molecular World p272-276 Objectives: to define DNA, cancer, viruses, prions,

DNA Cells perform many functions that are controlled by genes Genes are sections of DNA-deoxyribonucleic acid Found in the nucleus of all cells

DNA

DNA DNA is constructed from phosphates, sugars and 4 different nitrogenous bases: A - adenine T - thymine C - cytosine G - guanine

Gene Sequencing Determining the order of A,T,C,G in a gene Human genome project Completed in 2003 Mapped all the human genes (25 000 genes or 3 billion chemical base pairs !)

Why Sequence Genes Molecular medicine –cure diseases DNA forensics (identification) Agriculture, livestock breeding, and bioprocessing

Cancer Uncontrolled cell growth Caused by a change or mutation to genes Mutagens such as UV light cause mutations (although they can occur spontaneously)

A carcinogen is a substance that causes cancer Asbestos benzene

Viruses A non living, non cellular structure of DNA enclosed in a protein coating Cannot reproduce on its own, does not need energy, does not produce waste

Influenza and Adenovirus

A virus takes over a host cell and uses that host cell to make more viruses.

Prion A harmful protein that causes disease Ex) Spongiform Encephalopathy