Biomolecules assertion-reasons type questions

 

Assertion-Reason Type Question from Biomolecules

(A) Both assertion and reason are correct statements, and reason is the correct explanation of the assertion.

(B) Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion

(C)  Assertion is correct, but reason is wrong statement. 

(D)  Assertion is wrong, but reason is correct statement.

1. Assertion- sucrose is a non-reducing sugar.

        Reason-  it has glycosidic linkage

        Ans-b

     2. Assertion- Glucose and fructose can be distinguished by Tollen’s reagent.

        Reason- Glucose contains an aldehyde group while fructose contains a keto group.

        Ans-d

     3. Assertion- Carbohydrates were earlier called as hydrates of carbon.

        Reason – Carbohydrates can be hydrolysed.

       Ans- b (hydrates of carbon due to their general formula, C_x (H₂O)_y.

     4. Assertion- Starch is a non-sugar

        Reason- Starch is polysaccharides.

       Ans- b    (non-sugar means not sweet in taste)

    5. Assertion- Cellulose is a carbohydrate.

       Reason- Cellose has Molecular formula (C₆H₁₀O₅) _n

       Ans- a

    6. Assertion-all naturally occurring α- amino acids except glycine are optically active.

        Reason- Most naturally occurring amino acid acids have L- configuration.

        Ans- b

    7. Assertion- α- amino acids exist as internal salt in solution as these have amino and carboxylic group in vicinity.

      Reason- H⁺ ions given by carboxylic group (-COOH) is captured by amino group(-NH2) having lone pair of electrons

      Ans-a

    8. Assertion – Valine is non-essential amino acid.

       Reason - The lack of essential amino acids in the diet causes kwashiorkor.

      Ans- d

            Hint-      Essential amino acid (cannot synthesized in body)  example-Valine, Leucine, Isoleucine, Phenylalanine, Arginine, Threonine, Tryptophan, Methionine, Lysine, Arginine, Histidine

    9.     Assertion – solubilities of protein (which are made of α- amino acids) is minimum at the isoelectric point.

     Reason-At isoelectric point protein molecules stop behaving as  Zwitter ions

         Ans-a

          Hint- (the pH at which the lack of movement of ions during electrophoresis happens is known as isoelectronic point of amino acids i.e. no net charge

    10.  Assertion- α- amino acids exists as dipolar ions or Zwitter ions

           Reason- α- amino acids are the building blocks of protein.

          Ans- b

    11.  Assertion- Two strands are complementary to each other.

           Reason- The hydrogen bonds are formed between specific pairs of bases.

          Ans- a

    12.  Assertion- Two strands are complementary to each other.

          Reason- Disulphide bonds are formed between specific pairs of bases.

          Ans- c

    13.  Assertion- Glucose reacts with hydroxylamine to form an oxime and also adds a molecule of hydrogen cyanide to give cyanohydrin.

         Reason - The carbonyl group is present in the open chain structure of glucose.

         Ans-a

    14.  Assertion- proteins are made up α- amino acids.

            Reason- During denaturation, secondary and tertiary structure of proteins are destroyed

            Ans-b

    15.  Assertion- proteins are made up α- amino acids.

           Reason- During denaturation, secondary and tertiary structure of proteins are destroyed but primary remains intact

           Ans-b

   16.  Assertion – Denaturation of protein occurs in stomach.

           Reason – The enzymes pepsin, trypsin and chymotrypsin present in stomach hydrolyse proteins to α- amino acids.

         Ans- a

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