What dose denature mean and how dose it relate to enzyme function

Definition of Denature: to treat the by chemical or physical mean so as to alter its original state. Basically it means to change something from its original state (like at first an ice cream was cold, but the sun melted it and the ice cream became warm).

Relationship of enzyme function: Proteins change their shape as the temperature changes. Since the enzyme's activity is based on the shape, temperature change may mess up its process and then the enzyme will not work. High temperature will cause the enzyme to denature and the enzyme's structure will start to break up.