CBSE Guess > Papers > Important Questions > Class XII > 2013 > Chemistry > Biomolecules by Mr. R. Srinivas Vasudevamurthy

CBSE CLASS XII

Biomolecules - 4 Marks Questions

1. Mention the function of carbohydrates in plants.

2.  How are carbohydrates classified? Give one example each.

3. Fructose is a ketohexose but it is a reducing sugar. Why?

4. What are monosaccharides? Give two examples.

5. Write the equations of the reactions involved when glucose is reacted with

a) acetic anhydride
b) HI
c) Hydroxylamine
d) HCN
e) Br₂(aq)
f) concentrated HNO₃. Write the significance of each reaction.

6. Enumerate the reactions of glucose which can not be explained by open structures.

7. Draw the Howarth structures of

a) α-D-(+) glucopyranose
b) β-D-(+) glucopyranose
c) α-D-(-) fructo furanose
d) β-D-(-) fruco furanose

8. Draw the Howarth structure of

a) sucrose
b) maltose
c) lactose. Classify them as reducing or Non reducing sugar. Justify your answer.

9. Explain the terms

a) muta rotation
b) anomers.

10. Distinguish between

a) starch and cellulose
b) amylose and amylo pectin
c) starch and Glycogen.

11. Give the hydrolysis products of

a) sucrose
b) lactose
c) maltose.
d) DNA containing thymine

12. What is invert sugar? Why is it called so?

13. What are anomers? Draw the anomers of glucose. Are they enantiomers?

14. Classify the following as monosaccharides and disaccharides:

a) ribose
b) 2-Deoxy ribose
c) sucrose
d) galactose
e) lactose
f) maltose
g) fructose

15. Explain glycosidic linkage with an example.

16. Explain the following with respect to protein

a) primary structure of protein
b) secondary Structure of protein
c) tert structure of protein
d) quaternary structure of protein
e) native state of protein
f) denaturation of protein
g) zwitter ion

17. Explain peptide linkage with an example.

18. Mention the type of bonding in

a) α helix structure
b) β sheet structure
c) cross links of polypeptide chain
d) DNA

19. Name the forces which stabilize secondary and tert structure of protein.

20. Distinguish between

a) α helix and β sheet structure
b) fibrous and globular protein.
c) primary and secondary structure of protein
d) nucleoside and nucleotide

21. Account for the following;

a) Amino acids are more soluble and has higher melting point than halo acids.

b) Amino acids behave like salts rather than amines or carboxylic acids

c) Amino acids are amphoteric

d) On electrolysis amino acids migrate towards cathode in acid solution and anode in alkaline solution.

e) Mono amino mono carboxylic acid has two pk values.

f) Amino acids are optically active.

g) on boiling egg it becomes hard

22. Name and give the structure of amino acid which is optically inactive.

23. What are essential and non essential amino acids? Give two examples each.

24. What are enzymes? Explain the mechanism of enzyme catalysed reaction.

25. What are coenzymes? Give two examples.

26. What are vitamins? How are they classified?

27. Mention the sources of vitamin

a) A
b) C
c) D
d) E
e) K
f) B₁
g) B₂
h) B₆
i) B₁₂ . Name the diseases caused due to the deficiency of each vitamin.

28. Vitamin C can be taken regularly but not vitamin A Why?

29. What are nucleic acids? Mention the functions of nucleic acids.

30. Show the formation of a dinucleotide with an example.

31. Mention the differences between DNA and RNA.

32. Two strands of DNA are not identical but complementary. Explain this statement.

33. What are different types of RNA present in the cell.

34. Explain the terms

a) transcription
b) translation

35. What is the effect of denaturation of protein?

36. Where does the water present in egg go after boiling?

37. Base sequence in a DNA strand is ATTGCCA Give the base sequence

a) in its complementary strand
b) messenger RNA

38. When RNA is hydrolysed there is no relationship among the quantities of different base obtained. What does this fact suggest about the structure of RNA?

39. Draw the structures of sugars present in DNA and RNA.

 

Submitted By : Mr. R. Srinivas Vasudevamurthy
Email: [email protected]