Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Monosaccharides contain carbonyl group hence are classified, as aldose or ketose. The number of carbon atoms present in the monosaccharide molecule are also considered for classification. In which class of monosaccharide will you place fructose?

What are glycosidic linkages? In which type of biomolecules are they present?

Which monosaccharide units are present in starch, cellulose and glucose and which linkages link these units?

Assertion: Deoxyribose, \[\ce{C5H10O4}\] is not a carbohydrate.

Reason: Carbohydrates are hydrates of carbon so compounds which follow \[\ce{C_x(H2O)_y}\] formula are carbohydrates.

A natural linear polymer of 2-methyl-1, 3-butadiene becomes hard on treatment with sulphur between 373 to 415 K and – S – S – bonds are formed between chains. Write the structure of the product of this treatment?

Identify the type of polymer given in the following figure.

To have practical applications why are cross links required in rubber?

Why does cis-polyisoprene possess elastic property?

What is the structural difference between HDP and LDP? How does the structure account for different behaviour and nature, hence the use of a polymer?

Assertion: Network polymers are thermosetting.

Reason: Network polymers have high molecular mass.

Which is the correct statement about birth control pills?

The most useful classification of drugs for medicinal chemists is ______.

Which of the following statements are incorrect about receptor proteins?

(i) Majority of receptor proteins are embedded in the cell membranes.

(ii) The active site of receptor proteins opens on the inside region of the cell.

(iii) Chemical messengers are received at the binding sites of receptor proteins.

(iv) Shape of receptor doesn’t change during attachment of messenger.

Where are receptors located?

How are receptor proteins located in the cell membrane?

Match the class of compounds given in Column I with their functions given in Column II.

Assertion: Receptors are crucial to body’s communication process.

Reason: Receptors are proteins.

Assertion: Chemical messengers are chemicals that enable communication of message between two neurons or between neurons and muscles.

Reason: Chemicals enter the cell through receptor.

Assertion: Chemical messenger gives message to the cell without entering the cell.

Reason: Chemical messenger is received at the binding site of receptor proteins.

Assertion: Receptor proteins show selectivity for one chemical messenger over the other.

Reason: Chemical messenger binds to the receptor site and inhibits its natural function.