As shown in Figure 3, the enzyme has a particular shape that a substrate fits into. However, if environmental factors such as temperature or pH are altered and the shape of the active site changes, the enzyme is said to be ‘denatured’. While the enzyme is denatured it does not function. This can have a detrimental affect on the health of E.coli bacteria. In this investigation, the permissible temperature and pH ranges for growth were identified.