Question

Which of the statements about denaturation given below are correct?
(a) Denaturation of proteins causes loss of secondary and tertiary structures of the protein.
(b) Denaturation leads to the conversion of the double strand of DNA into the single strand.
(c) Denaturation affects primary structure which gets distorted.
A. (b) and (c)
B. (a) and (c)
C. (a) and (b)
D. (a), (b) and (c)

Answer 1

Hint: Denaturation is essentially a process during which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state. Upon being denatured proteins become non-functional.

Complete answer: Denaturation is a process during which proteins lose their secondary, tertiary and quaternary structures due to some external factors like heat, acid, base, etc. After denaturation of protein, it loses its 3D structure and, hence it doesn't function further, e.g. once we cook food, the proteins undergo denaturation, or once we heat DNA strands, the two strands of DNA separate from each other and we can easily obtain single strands. The temperature supplied pulls the two strands apart and, hence we get single strands. This particularly is what we know as DNA denaturation of DNA melting. Denaturation disrupts the normal alpha-helix and beta sheets in a protein and uncoils it into a random shape. It occurs because the bonding interactions responsible for the secondary structure and tertiary structures are disrupted. The tertiary structure in proteins involves the breaking down of covalent bonds between two amino acids. Enzymes lose their activity as substrates can no longer bind to the active site.
So, the correct answer is option C.

Note: Denaturation is very important in molecular tests. By understanding the properties of nucleic acid denaturation, the following methods were created: they are Polymerase chain reaction, Southern blotting, northern blotting and DNA sequencing.