Denaturation is a process from Biochemistry. In this process, the proteins or nucleic acids lose their structures through external stress or compounds. The external factors could be treatment with strong acids or bases, high concentrations of inorganic salts, organic solvents or heat etc. This results in disruption of cell activity and also death of the cell.
On the other hand, the process of coagulation is a process through which the blood forms clots. This is a very important process in animal body. Through this process, a damaged blood vessel wall is covered by a clot containing platelet and fibrin which stops the bleeding and starts the repair of the damaged vessel. Thus it becomes an important part of homeostasis.