Answer
A protein is said to be denatured when it has become disorganized and lost its shape. in such condition the protein is non functional because the organization of protein exist no more which is important for their proper function.
Forexample
Hemoglobin is a protein molecule composed of four polypeptide chain and 574 amino acids and arrange in Quaternary structure. when its structure is disorganized then its unable to transport oxygen.
