Write one difference between α -helix and β -pleated structures of proteins.

Amino acids show amphoteric behaviour. Why?

Deficiency of which vitamin causes degeneration of spinal cord?

• E

• K

• B₁₂

• A

Define the following terms as related to proteins:

(i) Peptide linkage
(ii) Primary structure
(iii) Denaturation

Define the following with an example:

Denatured protein

Define the following with an example:

Polysaccharides

Write the product when D-glucose reacts with conc. HNO₃

Define the following with an example:

Essential amino acids

After watching a programme on TV about the presence of carcinogens(cancer causing
agents) Potassium bromate and Potassium iodate in bread and other bakery products, Ritu a class XII student decided to aware others about the adverse effects of these carcinogens in foods. She consulted the school principal and requested him to instruct canteen contractor to stop selling sandwiches, pizza, burgers and other bakery products to the students. Principal took an immediate action and instructed the canteen contractor to replace the bakery products with some proteins and vitamins rich food like fruits, salads, sprouts etc. The decision was welcomed by the parents and students.

After reading the above passage, answer the following questions :
(i) What are the values (at least two) displayed by Ritu?
(ii) Which polysaccharide component of carbohydrates is commonly present in bread?
(iii) Write the two types of secondary structure of proteins.
(iv) Give two examples of water soluble vitamins.

One mole of stachyose on hydrolysis yields

• 1 mole of glucose+ 1 mole of fructose+ 2 mole of galactose

• 2 mole of glucose + 1 mole of fructose + 1 mole of galactose

• 1 mole of glucose+ 2 mole of fructose+ 1 mole of galactose

• 2 mole of glucose+ 2 mole of fructose