There is Case Study Questions in class 12 Chemistry in session 2020-21. For the first time, the board has introduced the case study questions in the board exam. The first two questions in the board exam question paper will be based on Case Study and Assertion & Reason. The first question will have 5 MCQs out of which students will have to attempt any 4 questions. The second question will carry 5 Assertion & Reason type questions with the choice to attempt any four. Here are the questions based on case study.
Case Study Question 1:
Read the passage given below and answer the following questions:
When a protein in its native form, is subjected to physical changes like change in temperature or chemical changes like change in pH, the hydrogen bonds are disturbed. Due to this, globules unfold and helix get uncoiled and protein loses its biological activity. This is called denaturation of protein.
The denaturation causes change in secondary and tertiary structures but primary structures remains intact.
Examples of denaturation of protein are coagulation of egg white on boiling, curding of milk, formation of cheese when an acid is added to milk.
The following questions are multiple choice question. Choose the most appropriate answer:
(i) Mark the wrong statement about denaturation of proteins.
(a) The primary structure of the protein does not change.
(b) Globular proteins are converted into fibrous proteins.
(c) Fibrous proteins are converted into globular proteins.
(d) The biological activity of the protein is destroyed.
(ii) Which statement(s) of protein remain(s) intact during denaturation process?
(a) Both secondary and tertiary structures
(b) primary structure only
(c) secondary structure only
(d) tertiary structure
(iii) α-helix and β-pleated structures of proteins are classified as
(a) primary structure
(b) secondary structures
(c) tertiary structure
(d) quaternary structure
or
Cheese is a
(a) globular protein
(b) conjugated protein
(c) denatured protein
(d) derived protein
(iv) Secondary structure of protein refers to v(a) mainly denatured of proteins and structures of prosthetic groups
(b) three-dimensional structure, especially the bond between amino acid residues that are distant from each other in the polypeptide chain
(c) linear sequence of amino acid residues in the polypeptide chain
(d) regular folding patterns of continuous portions of the polypeptide chain.
Answers
(i) c(ii) b
(iii) b
or
c
(iv) d