Denaturation occurs when the environment around has a extremely high temperature of extreme pH values comparing to the optimum values of the enzyme. Each enzyme has their own optimum temperature and pH.
In the case, the lost its three-dimensional structure and can no longer function because the shape of the active site is altered and thus it can no longer bind into substrates.
scientist has estimated that over 8.7million species in the world of plants and animals in existence, though as few as 6.5million on land and 2.2million in the ocean