Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): During the curding of milk, the primary structure of milk proteins remains intact. Reason (R): Curding of milk is caused by bacteria due to the formation of lactic acid. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

Curding of milk is an example of denaturation of proteins. During denaturation, the secondary and tertiary structures are destroyed, but the primary structure remains intact. Therefore, Assertion (A) is true. Curding of milk is indeed caused by bacteria due to the formation of lactic acid, which lowers the pH and triggers denaturation. Therefore, Reason (R) is true. However, Reason (R) explains the chemical cause of the curding process, not why the primary structure remains intact. The primary structure remains int