Biomolecules Mock Test – Class 11 Biology

1. A dry sample contains carbon, hydrogen, oxygen, sodium, calcium and magnesium. Quantitative analysis shows high carbon and hydrogen percentages, a high oxygen percentage and very little silicon. Which interpretation is most defensible?

2. Analyse the fractionation records below.

Which pair best demonstrates that the same fraction can contain substances for different structural reasons?

3. A purified enzyme is active before treatment. After its required metal ion is removed, the protein remains intact but activity becomes undetectable. Re-addition of the same metal restores activity, whereas addition of an unrelated metal does not. Which conclusion is best supported?

4. Review the protein-function records below.

Which record requires correction?

5. Complete hydrolysis of a purified ribozyme produces small nucleotide-related units that remain water-soluble. Which combined change is most likely?

6. Let represent wet mass, dry mass, ash mass, water mass and combustible matter. Which set of relations correctly represents the drying-and-combustion analysis?

7. Consider the following statements about nucleic acids.
I. DNA and RNA are polynucleotides.
II. Their repeating units are nucleotides containing a base, pentose and phosphate.
III. They are true biomacromolecular polymers.
IV. A single nucleoside is itself a complete polynucleotide.

8. Arrange the following events in the order that produces a polypeptide from separate amino acids.
P. Individual amino acids are available.
Q. Adjacent amino-acid residues become linked by peptide bonds.
R. The linked chain lengthens through additional amino-acid residues.
S. A linear polypeptide with a definite residue order is obtained.

9. The pathway outcomes are summarised below.

Which interpretation is supported?

10. Match each substance with the fraction in which it is expected to occur predominantly after trichloroacetic-acid extraction. Column II entries may be reused.

11. A learner reads an enzyme graph and states, “ is the velocity equal to .” What correction is required?

12. Match each change with its classification. A Column II entry may be reused.

13. A cell preparation has a total mass of . Water forms and proteins form of this mass. By how much does the water mass exceed the protein mass?

14. Succinic dehydrogenase is tested under four conditions.

Which interpretation best fits the complete data?

15. An unknown polysaccharide becomes blue after iodine addition. In the same experiment, a starch control becomes blue and a cellulose control remains unchanged. Which conclusion is most justified?

16. An acid-insoluble tissue fraction is divided into two equal portions. Treatment of Portion P releases many nucleotide units. Treatment of Portion Q releases fatty acids and glycerol. Which interpretation is best supported?

17. After a reaction has gone to completion, the enzyme is separated from the product and found to have the same primary structure and catalytic capacity it had initially. This observation most directly demonstrates that:

18. Let be the set of organic substances recovered in the acid-insoluble fraction, the set of true biomacromolecular polymers and the set of membrane lipids retained during fractionation. Which relation best represents the biological pattern?

19. The concentration of active enzyme in a reaction mixture is doubled while substrate range, pH and temperature remain unchanged. Which combined graph prediction is most appropriate?

20. Two enzyme samples show equally low activity at moderate substrate concentration. Sample P contains a competitive inhibitor. Sample Q lacks an essential cofactor. Substrate concentration is then increased greatly without changing any other condition. Which result is most likely?

21. Consider the following statements about a complete enzyme catalytic cycle.
I. Substrate binding produces an enzyme-substrate complex.
II. The active site promotes bond breaking or bond formation.
III. Product may remain briefly bound in an enzyme-product complex.
IV. Product release restores enzyme that can begin another cycle.

22. Consider the following statements about chemical analysis of living tissue.
I. Elemental analysis can show that living and non-living matter contain many of the same elements but in different relative abundances.
II. Compound analysis identifies molecular classes such as amino acids, sugars, proteins and lipids.
III. Ash represents inorganic residue remaining after combustible matter is removed.
IV. Acid-soluble and acid-insoluble fractions together provide broader information than either fraction alone.

23. Evaluate the following statements about purines and pyrimidines.
I. Adenine and guanine are purines.
II. Cytosine, uracil and thymine are pyrimidines.
III. The attached pentose determines whether a base is purine or pyrimidine.
IV. All five named compounds are nitrogenous heterocyclic bases.

24. Evaluate the following statements about the chemical basis of living systems.
I. The atoms present in a cell are individually non-living.
II. Cellular organisation influences the biological effects of molecules.
III. Continuous chemical transformations are essential to living activity.
IV. An isolated biomolecule need not display all properties of a living organism.

25. Use the arrangement described below. A substrate occupies a pocket in an enzyme, and the enzyme has fitted more tightly around it. Product has not yet formed, and the substrate remains chemically identifiable. The arrangement most directly represents:

26. Match each amino acid with the description that applies most directly. A Column II entry is used once.

27. Structural resemblance to the substrate allows a competitive inhibitor to compete for the enzyme's ______.

28. A polypeptide is represented only as a linear list of residues from Position to Position : . No folding or subunit association is shown. The representation describes:

29. The group counts of three amino acids are summarised below.

How should P, Q and R be classified?

30. A nucleotide is treated so that its phosphate group is removed without breaking the bond between its nitrogenous base and sugar. The remaining product is classified as:

31. Water contributes about of cellular mass, while proteins contribute about . What is the smallest possible water-to-protein percentage ratio within these ranges?

32. A fractionation arrangement has Region P as the filtrate containing amino acids, sugars, ions and other soluble cytoplasmic constituents. Region Q is the retained material containing proteins, nucleic acids, polysaccharides and membrane fragments from cytoplasm and organelles. Which interpretation is appropriate?

33. Examine the metabolite records below.

Which classification best fits the complete evidence?

34. In the stated pathway overview, one glucose molecule produces molecules of pyruvic acid through enzyme-catalysed reactions. If glucose molecules complete the pathway, how many pyruvic-acid molecules are produced?

35. Select the arrangement that correctly places the stated examples into acidic, basic and neutral amino-acid categories, respectively.

36. Assertion: A single nucleotide is itself a polynucleotide and can be classified as a complete nucleic-acid polymer.
Reason: A nucleic acid contains many nucleotide units arranged in a polymeric chain.

37. A researcher homogenises tissue in trichloroacetic acid but forgets to filter the mixture. The researcher then labels the entire homogenate as the acid-soluble pool. What is the main error in this interpretation?

38. The reaction

is best described as:

39. A pathway contains the reactions shown below.



Which classification of , and is correct?

40. One record in the table is incorrectly classified.

Which correction is required?

41. Evaluate the following statements about destructive analysis of tissue.
I. Dry weight excludes the water removed during drying.
II. Dry matter contains both organic and inorganic constituents before burning.
III. Complete burning removes carbon compounds while leaving inorganic ash.
IV. The difference between dry mass and ash mass estimates combustible organic material.

42. Four enzyme-catalysed reactions are summarised below.

Which ordered classification is correct?

43. A reaction transfers hydrogen-related reducing equivalents from one substrate to another. One substrate becomes oxidised and the other becomes reduced. Why is the enzyme classified as an oxidoreductase rather than an ordinary transferase?

44. Enzyme converts B into C but cannot act on A. In one tube, A is mixed only with , and no C forms. In another tube, A is first treated with , which produces B, and addition of then produces C. What is the strongest conclusion?

45. Assertion: An elemental analysis showing carbon, hydrogen and oxygen cannot by itself establish that glucose is present in a tissue.
Reason: The same elements can occur in many different compounds, so compound identity requires additional separation and analytical evidence.

46. Consider the following statements about polysaccharides.
I. They are long chains built from monosaccharide units.
II. Their constituent sugar units may be of one type or more than one type.
III. They are generally included among true biomacromolecular polymers.
IV. Every polysaccharide performs only an energy-storage function.

47. The molecular feature that makes a protein a polypeptide is:

48. Consider the following statements about enzyme nomenclature and classification.
I. The stated system recognises six major classes.
II. Classification depends on the reaction an enzyme catalyses.
III. A class may contain approximately subclasses.
IV. A four-digit number represents an enzyme's position in the classification.

49. Arrange the stages that lead from a crude tissue extract to information about an individual compound.
P. Separate components of the extract.
Q. Isolate the compound of interest.
R. Purify the isolated compound.
S. Apply analytical methods to determine its molecular formula and probable structure.

50. Two purified triglycerides contain the same glycerol backbone and the same number of esterified fatty acids. Lipid P contains no bonds and melts at a higher temperature than Lipid Q, whose fatty acids contain several bonds. Which conclusion is best supported?