Question

Protein denaturation result in:

(A) Change of primary stricture

(B) Change in secondary structure

(C) Change in tertiary structure

(D) Change in both secondary and tertiary structure

Answer 1

Hint Physical change like change in temperature and chemical change like change in pH due to which the hydrogen bond of an amino acid polymer gets disturbed. Due to this, globules unfold and the helix gets uncoiled and finally a protein molecule loses its biological property. This is known as denaturation of protein. Coagulation of egg white on boiling and curdling of milk by acid is the common example of denaturation of protein.

Complete answer–

During denaturation the secondary and tertiary structure of protein gets destroyed but the primary structure remains unchanged. If change in the medium is mild and for a short period of time then denaturation of protein will be temporary, but if the change in the medium is strong and prolonged the protein will be permanently denatured.

Protein is a polymer of amino acid and contains polypeptide and hydrogen bonds. Property of protein depends on the sequence of amino acids and configuration of protein. Configuration of protein is determined by polypeptide and hydrogen bond.

Beside change in pH and temperature high metal, salt and high pressure also causes precipitation of protein. Because of these changes the secondary and tertiary structure of protein is destroyed and protein gets coagulated. Such alteration in the physical activity of protein is called denaturation.

In a biological system, a protein has a unique three dimensional structure and a unique biological activity in such a situation the protein is called native protein. When a native protein is subjected to high temperature and pH, its H-bonds get disturb this disturbance unfolds the globular stricter and uncoils the helix structure of protein.

Option (D) is correct.

Note – The primary structure of protein amino acid is linked together by peptide bonds and these bonds remain stable in high temperatures. However, the secondary and tertiary structure of protein contains hydrogen bonds along with peptide bonds. Hydrogen bonds break down and disturbed in high temperatures and ph.