UNIT-14 : BIOMOLECULES

One mark questions:

1. What are monosaccharides? K
2. What are oligosaccharides ? K
3. Is galactose an aldose or ketose sugar ? U
4. What are reducing sugars? K
5. What is the product obtained when glucose is oxidised by bromine water? K

6. Glucose 
 X. What is X?
oxidation with nitric acid K

7. Identify the monomer for the polysaccharide :

7. How do you account for the absence of free aldehyde group in the pentaacetate
of D-glucose? K

8. What is an anomeric carbon? K

9. Write the Haworth's structure for -D () fructofuranose. K
10. What do you mean by glycosidic linkage? K
11. During curdling of milk, what happens to sugar present in it? K
12. Name the water soluble component of starch. K
13. Give the general representation for -L- amino acid. K
14. The solubility of amino acids in water are generally higher than that of the
corresponding halo acids. Explain. U
15. How many peptide bonds are present in a pentapeptide? K
16. Maya is suffering from Pernicious anaemia . Name the vitamin deficient in her. U
17. Name the vitamin whose deficiency in our body results in impaired clotting of
blood. K
18. Name a hormone which controls the level of excretion of water and salt from
kidneys. K
19. Vitamins are classified into two groups depending upon their solubility in water or
fat. In which class will you place vitamin D ? U
20. Name the sugar moiety present in DNA molecule. K
21. What is the difference between a nucleoside and a nucleotide? U

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Two mark questions:
1. What are disaccharides? Give an example. K
2. What are polysaccharides ? Give an example. K
3. What reactions of glucose support to show that :
i) it has a carbonyl group ii) it has a chain of six carbon atoms? K
4. Mention two reactions and facts that cannot be explained by the open chain
structure of glucose. K
5. How do the two cyclic hemiacetal forms of glucose differ? What are these two
forms called? K
6. What are the hydrolytic products of maltose? Why is it a reducing sugar? K
7. What is the composition of invert sugar? How is it obtained? U
8. Give two differences between amylose and amylopectin units of starch. U
9. What is the basic structural difference between starch and cellulose? U
10. Write two main functions of carbohydrates in plants. K
11. Write the zwitter ion form of -amino acid. In this form amino acids are
amphoteric. Give reason. K
12. Give the name and structure of the simplest α- amino acid which is optically
inactive . K
13. Draw the structure of Glycylalanine. Mark the peptide linkage in it. K
14. Vitamin C cannot be stored in our body. Why? U
15. Name the hormone which contains iodine. What is the function of this hormone? K
16. What are the common types of secondary structures of proteins? K
17. The two strands in DNA are not identical but are complementary. Explain. K
Three mark questions:
1. With respect to the sugar in milk:
i) name the sugar ii) name the hydrolytic products of the sugar
iii) which carbon atoms are involved in the formation of glycoside bond in it? U
2. What does , D, (+) in the name   D (+) glucose signify? U
3. i) Write the Haworth's structure of D(+) sucrose:
ii) Sucrose is a non-reducing sugar. Why?
iii) What is the main source of sucrose? U
4. From the following polysaccharides : glycogen, cellulose, amylose, answer the
followings:
i) Which one is a linear polymer of - glucose ?

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 ii) Which one is a polymer of  – glucose ?
iii) Which one is a polymer present in liver and muscle ? U
5. What is glycogen? How is it different from starch? U
6. What type of linkages are responsible for the formation of
i) Primary structure of proteins
ii) Cross linking of polypeptide chains
iii) -helix formation? U
7. Match the items in A, B and C correctly
A B C
a) Valine Non essential amino acid Basic amino acid
b) Aspartic acid Essential amino acid Neutral amino acid
c) Lysine Essential amino acid Acidic amino acid K

8. What are essential and non-essential amino acids? Is glycine an essential or non-
essential amino acid? K

9. What are these with respect to proteins

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

10. Explain the terms primary and secondary structure of proteins. What is the
difference between -helix and -pleated sheet structure of proteins? U

11. Differentiate between globular and fibrous proteins with one example for each. U

12. What is a native protein? Explain how it gets denatured? U

13. What are the forces that stabilises the 2° and 3° structures of proteins? K

14. How are vitamins classified? Name the vitamin deficiency of which leads to
convulsions? K

15. Why are vitamin A and vitamin C essential to us? Mention one source for
vitamin C. K

16. Name:
i) a water soluble vitamin.
ii) a fat soluble vitamin.
iii) the disease caused by deficiency of vitamin D. K

17. Match the items in A, B and C correctly:

A B C
a) Vitamin A Green vegetables Scurvy
b) Vitamin C Carrot Beri beri K

c) Vitamin B1 Citrus fruit Night blindness

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18. Match the items in A, B and C correctly:
A B C
a) Glucagon pancreas Decreases blood glucose
b) Thyroxin Pancreas Increases blood glucose K
c) Insulin Thyroid Stimulates metabolism
19. What are nucleic acids? Mention their two important functions. K
20. Write the important functional differences between DNA and RNA. K
21. Name the products that would be formed when a nucleotide is completely
hydrolysed? K
22. Name the linkage that joins:
i) two monosaccharides ii) two -amino acids iii) two nucleotides K

23. What information can you get from 1° and 2° structure of DNA? How is the 2°
structure of DNA stabilised? K

24. Give differences between RNA and DNA with respect to :

i) sugar moiety ii) N-base iii) structure K

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