Biomolecules

Q1. The length of one turn of the helix in a B-form DNA is approximately?

1. 3.4nm.
2. 0.34nm.
3. Both.
4. None of these.

Q2. The basic unit of nucleic acid is:

1. Pentose sugar.
2. Nucleoid.
3. Nucleoside.
4. Nucleotide.

Q3. Enzymes increase the rate of reaction by:

1. Lowering activation energy.
2. Increasing activation energy.
3. Increasing temperature and pH.
4. Decreasing temperature and pH.

Q4. The most basic amino acid is:

1. Arginine.
2. Glycine.
3. Histidine.
4. Glutamine.

Q5. Enzymes that catalyze the removal of groups from substrates by mechanisms other than hydrolysis, and the addition of
groups to double bonds, are called:

1. Lyases.
2. Dehydrogenases.
3. Both.
4. None of these.

Q6. Which of the following is a basic amino acid?

1. Serine.
2. Glycine.
3. Methionine.
4. Lysine.

Q7. Which is an essential amino acid?

1. Serine.
2. Aspartic acid
3. Glycine.
4. Phenylalanine.

Q8. Cytochrome is:

1. Metallo flavoprotein.
2. Fe containing porphyrin pigment.
3. Glycoprotein.
4. Lipid.

Q9. A homopolymer has only one type of building block called monomer repeated ‘n’ a number of times. A
heteropolymer has more than one type of monomer. Proteins are heteropolymers usually made of.

1. 20 types of monomers.
2. 40 types of monomers.
3. 30 types of monomers.
4. only one type of monomerually made of

Q10. In plants, inulin and pectin are:

1. Reserve materials.
2. Wastes.
3. Excretory material.
4. Insect-attracting material.

Q11. NADP contains vitamin _.

1. B1
2. B2
3. B3
4. B12

Q12. Enzymes enhance the rate of reaction by:

1. Forming a reactant-product complex.
2. Changing the equilibrium point of the reaction.
3. Combining with the product as soon as it is formed.
4. Lowering the activation energy of the reaction.

Q13. Which of the following sets contains polysaccharides?

1. Starch, glycogen, cellulose.
2. Sucrose, maltose, cellulose.
3. Galactose, starch, sucrose.
4. Glucose, fructose, lactose.

Q14. Enzymes having slightly different molecular structure but performing identical activity are:

1. Homoenzymes.
2. Isoenzymes.
3. Apoenzymes.
4. Coenzymes.

Q15. ATP is a:

1. Nucleotide.
2. Nucleosome.
3. Nucleoside.
4. Purine.

Q16. Lecithin is a:

1. Polysaccharide
2. Protein
3. Nucleic acid
4. Lipid

Q17. The transfer RNA molecule in 3D appears.

1. L-shaped.
2. E-shaped.
3. Y-shaped.
4. S-shaped.

Q18. The fastest enzyme known is:

1. DNA polymerase.
2. Carbonic anhydrase.
3. Carbonic dehydrogenase.
4. DNA ligase.

Q19. An example of competitive inhibition of an enzyme is the inhibition of:

1. Succinic dehydrogenase by malonic acid.
2. Cytochrome oxidase by cyanide.
3. Hexokinase by glucose-6-phosphate.
4. Carbonic anhydrase by carbon dioxide.

Q20. With reference to enzymes, which one of the following statements is true?

1. Apoenzyme = Holoenzyme + Coenzyme.
2. Holoenzyme = Apoenzyme + Coenzyme.
3. Coenzyme = Apoenzyme + Holoenzyme.
4. Holoenzyme = Coenzyme – Apoenzyme.

Q21. Glycogen is a polymer of:

1. Glucose.
2. Sucrose.
3. Galactose.
4. Fructose.

Q23. A segment of DNA has 120 adenine and 120 cytosine bases. The total number of nucleotides present in the segment is:

1. 120
2. 240
3. 60
4. 480

Q24. Types of RNA polymerase required in the nucleus for RNA synthesis.

1. 1
2. 2
3. 3
4. 4

Q25. Protein synthesis in an animal cell takes place.

1. Only in the cytoplasm.
2. In the nucleolus as well as in cytoplasm.
3. In cytoplasm as well as in mitochondria.
4. Only on ribosomes attached to the nuclear envelope.

Q26. Which among the following is a homopolysaccharide?

1. Maltose.
2. Chitin.
3. Sucrose.
4. Cellulose.

Q27. Living cell contains 60-75% water. Water present in the human body is:

1. 60-65%
2. 50-55%
3. 75-80%
4. 65-70%

Q28. Glycogen is a homopolymer made of.

1. Glucose units.
2. Galactose units.
3. Ribose units.
4. Aminoacids.

Q29. DNA synthesis can be specifically measured by estimating the incorporation of radio labelled.

1. Uracil.
2. Adenine.
3. Thymidine.
4. Deoxyribose sugar.

Q30. The pyrenoids are made up of:

1. Proteinaceous centre and starchy sheath.
2. The core of protein is surrounded by a fatty sheath.
3. Core of starch surrounded by sheath of protein.
4. The core of nucleic acid is surrounded by a protein sheath.

Q31. An aminoacid under certain conditions have both positive and negative charges simultaneously in the same
molecule. Such a form of aminoacid is called.

1. Acidic form.
2. Basic form.
3. Aromatic form.
4. Zwitterionic form.

Q32. What is common among amylase, rennin and trypsin?

1. These are all proteins.
2. These are proteolytic enzymes.
3. These are produced in the stomach.
4. These act at a pH lower than 7.

Q33. Carrier ions like Na facilitate the absorption of substances like:

1. Amino acids and glucose.
2. Glucose and fatty acids.
3. Fatty acids and glycerol.
4. Fructose and some amino acid.

Q34. A protein having both structural and enzymatic traits is:

1. Collagen
2. Trypsin
3. Myosin
4. Actin

Q35. Enzymes are biocatalysts. They catalyze biochemical reactions. In general, they reduce the activation energy of reactions. Many physico-chemical processes are enzyme-mediated. Which of the following reactions is not
enzyme-mediated in the biological system?

1. Dissolving CO in water.
2. Untwining the two strands of DNA.
3. Hydrolysis of sucrose.
4. Formation of peptide bond.

Q36. Most diverse macromolecules, found in the cell both physically and chemically are:

1. Proteins.
2. Carbohydrates.
3. Nucleic acids.
4. Lipids.

Q37. Essential amino acids include.

1. Valine.
2. Leucine.
3. Tryptophan.
4. All of these.

Q38. Aromatic amino acids contain which reactive group?

1. Ethyl.
2. Ketone.
3. Benzene.
4. Hydroxil.

Q39. The number of ‘ends’ in a glycogen molecule would be.

1. Equal to the number of branches plus one.
2. Equal to the number of branch points.
3. One.
4. Two, one on the left side and another on the right side.

Q40. Inhibitor binds to the active site of the enzyme. Hence blocking the reaction. This is an example of:

1. Allosteric inhibition.
2. Feedback inhibition.
3. Uncompetitive inhibition.
4. Competitive inhibition.