COMPASSLearning
RegisterLogin

JEE Main · 2020 · 04 Sep 2020 · Shift 1 · Biomolecules

WhatsApp Email
What are the functional groups present in the structure of maltose?
  1. (A)One acetal and one hemiacetal✓ Correct
  2. (B)One ketal and one hemiketal
  3. (C)One acetal and one ketal
  4. (D)Two acetals

Answer: (A)

Solution

Maltose is two glucose units joined by an glycosidic link. At that linkage the carbon carries two groups, which is an acetal. The second glucose keeps a free anomeric carbon at the reducing end, in equilibrium between the open-chain aldehyde and the cyclic form that has one and one on that carbon, which is a hemiacetal. So maltose contains one acetal and one hemiacetal.

JEE Main · 2020 · 04 Sep 2020 · Shift 1 · Single correct option

Practise more: all JEE Main PYQs on Biomolecules →

More JEE Main questions on Biomolecules

  1. Identify the correct statements.

    A. Arginine and Tryptophan are essential amino acids.
    B. Histidine does not contain heterocyclic ring in its structure.
    C. Proline is a six membered cyclic ring amino acid.
    D. Glycine does not have chiral centre.
    E. Cysteine has characteristic fe …
    JEE Main 2026View solution →
  2. Given below are two statements:

    Statement I: Sucrose is dextrorotatory. However sucrose upon hydrolysis gives a solution having mixture of products. This solution shows laevorotation.

    Statement II : Hydrolysis of sucrose gives glucose and fructose. Since the laevorotation of gl …
    JEE Main 2026View solution →
  3. The correct statements are:
    A. Activation energy for enzyme catalysed hydrolysis of sucrose is lower than that of acid catalysed hydrolysis.
    B. During denaturation, secondary and tertiary structures of a protein are destroyed but primary structure remains intact.
    C. Nucleotides a …
    JEE Main 2026View solution →
  4. Match List-I with List-II.

    List-I
    Reaction of glucose with
    A. Hydroxylamine
    B. water
    C. Excess acetic anhydride
    D. Concentrated

    List-II
    Product formed
    I. Glouconic acid
    II. Glucose pentacetate
    III. Saccharic acid
    IV. Glucoxime

    Choose th …
    JEE Main 2026View solution →
  5. Both human DNA and RNA are chiral molecules. The chirality in DNA and RNA arises due to the presence of
    JEE Main 2026View solution →
  6. The number of possible tripeptides formed involving alanine (ala), glycine (gly) and valine (val), where no amino acid has been used more than once is :
    JEE Main 2026View solution →