Biomolecules Mock Test – Class 11 Biology

1. Match each activity factor with its most direct stated effect. A Column II entry is used once.

2. A fresh tissue sample has a wet mass of , a dry mass of and an ash mass of . Which set correctly gives the masses of water, combustible organic material and inorganic residue?

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

4. A learner states, “The highest substrate concentration on a saturation graph is the enzyme's optimum substrate concentration, just as the peak of a pH graph is the optimum pH.” Which correction is required?

5. Assertion: Replacing ribose with -deoxyribose in a base–sugar–phosphate unit changes it from an RNA-type nucleotide to a DNA-type nucleotide.
Reason: Pentose identity distinguishes the stated DNA and RNA nucleotide types, while retained phosphate preserves nucleotide status.

6. Four unknown cellular molecules are summarised below.

Which synthesis is correct?

7. An inactive protein preparation is analysed. It contains the complete polypeptide sequence but lacks a non-protein component. The missing component is organic, remains tightly bound in the normal enzyme and forms part of its active site. Which sequence correctly describes restoration of activity?

8. Four molecular records are shown below.

Which records are correctly classified?

9. An RNA-type nucleotide undergoes two changes: ribose is replaced by -deoxyribose, and phosphate is subsequently removed. The nitrogenous base remains unchanged. What is the final product?

10. Match each protein structural level with its defining feature. A Column II entry is used once.

11. Organic molecule Q binds temporarily to Enzyme P, leaves after the reaction and later participates with Enzyme R. It is not permanently attached to either protein. Molecule Q is most appropriately described as:

12. Match each compound with its secondary-metabolite category. Column II entries may be reused.

13. A fatty acid has an -group containing carbon atoms. Including the carboxyl carbon, how many carbon atoms are present in the complete fatty-acid molecule?

14. An acid-insoluble cellular molecule is a high-molecular-mass polymer of ribonucleotides. The purified molecule accelerates a specific chemical reaction even though no polypeptide is present. Which identification best fits all the evidence?

15. A purified acid-insoluble polymer contains several hundred covalently joined sugar units and no amino-acid or nucleotide backbone. The most appropriate term for this molecule is ______.

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

17. Arrange the events in a simple metabolic pathway in their logical order.
P. The initial substrate binds to the enzyme catalysing the first step.
Q. An intermediate is formed and released.
R. The intermediate becomes the substrate for a later enzyme.
S. A later product is formed.

18. Let and be the substrate and product energy levels. Let and be the transition-state peaks for uncatalysed and catalysed routes. Which relation correctly represents enzyme action?

19. Consider the following statements about carbohydrate structure and function.
I. Starch and cellulose can both be glucose homopolymers yet differ in function and iodine response.
II. Glycogen is a branched glucose storage polymer associated with animals.
III. Inulin is identified as a fructose polymer.
IV. Chitin is classified as a protein because its modified sugar units may contain nitrogen.

20. 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?

21. Assertion: Adenine and guanine are both purine bases.
Reason: A nitrogenous base is classified as a purine only when it is attached to -deoxyribose.

22. Substance P is a stable substrate before binding. Arrangement Q is extremely short-lived, lies at a higher potential-energy level and contains bonds in the process of rearrangement. Product R has completed bonds and is released. How should Q be classified?

23. During enzyme action, the short-lived unstable higher-energy arrangement formed as substrate bonds are being broken or created is called ______.

24. For the same chemical reaction, an enzyme lowers the transition-state peak while substrate and product energy levels remain unchanged. An independent rate experiment shows more product formed per second in the enzyme-containing tube. Which relationship best integrates the two observations?

25. 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.

26. 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.

27. 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?

28. Suppose membrane lipids remained completely dispersed as independent water-soluble molecules after tissue disruption, while their molecular structures remained unchanged. What change would be most likely during fractionation?

29. Assertion: A zwitterionic amino acid may have no net charge even though it contains charged groups.
Reason: Its protonated amino group carries a positive charge while its deprotonated carboxyl group carries a negative charge.

30. Assertion: Reaction rate and velocity are completely identical terms in every scientific sense.
Reason: Velocity includes a directional specification, whereas rate describes the magnitude of change per unit time.

31. Combustion of a purified enzyme preparation leaves a small amount of zinc-containing ash. Removing zinc from an unburned sample abolishes catalytic activity, and adding restores it. The polypeptide sequence remains unchanged throughout the removal-and-restoration experiment. What is the strongest conclusion?

32. A low-molecular-mass compound is found only in a limited group of plants. It is not required as a universal monomer of proteins, polysaccharides or nucleic acids, and evidence suggests that it discourages herbivores. Which description is most appropriate?

33. An acid-insoluble compound is a long chain that yields numerous monosaccharide molecules when completely broken into its building units. It is most appropriately classified as:

34. Use the arrangement described below. Residues P, Q, R and S lie in one linear chain. Each residue contributes an amino-acid backbone and a variable side chain. The labelled links between successive residues join the carboxyl portion of one residue to the amino portion of the next. These labelled links are:

35. Three unknown amino acids are examined. Substance P has equal numbers of amino and carboxyl groups. Substance Q has one additional carboxyl group, while Substance R has one additional amino group. Which comparison with the stated examples is appropriate?

36. Both reactions occur in aqueous solution, but water appears as a reactant only in the first.


How should the enzymes catalysing the first and second reactions be classified, respectively?

37. Equal amounts of an enzyme are tested under the conditions shown below.

Which conclusion is most strongly supported?

38. Product formation was measured for three reactions.

Which reaction has the greatest average rate?

39. Assertion: Two proteins with identical amino-acid composition can have different biological functions.
Reason: Different residue orders can produce different primary structures, folds and functional sites.

40. A linear polypeptide has four labelled residues. P is the first residue, S is the last residue, Q lies immediately after P, and R lies between Q and S. What is the sequence from the N-terminal end to the C-terminal end?

41. During tissue extraction, lipids with individual molecular masses between and are recovered mainly with water-insoluble membrane fragments rather than in the filtrate. What is the strongest inference?

42. A nucleotide is described as containing a purine base, ribose and phosphate. What can be concluded from the supplied components?

43. Which statements together describe chemical interpretation of tissue fractions?
I. The acid-soluble pool roughly represents soluble cytoplasmic composition.
II. Macromolecules from cytoplasm and organelles contribute to the acid-insoluble fraction.
III. Membrane-derived lipid material may also occur in the insoluble fraction.
IV. The two fractions together provide a broader account of tissue composition than either fraction alone.

44. Equal masses of purified starch and cellulose are completely hydrolysed, and both yield glucose. Before hydrolysis, only starch gives a blue iodine response. Which inference is best supported?

45. Molecule P is a folded protein that accelerates a reaction. Molecule Q is an RNA molecule that also accelerates a specific reaction. Their relationship is best described as:

46. Assess the following statements about preparing a tissue extract with trichloroacetic acid.
I. Grinding increases contact between tissue contents and the extraction medium.
II. The product before filtration is a slurry.
III. Filtration directly reveals the molecular formula of each separated compound.
IV. The preparation enables separation into operationally soluble and insoluble fractions.

47. Study the abundance records below.

Which conclusion best integrates the two records?

48. Two glyceride samples are kept at the same winter temperature. Sample P remains liquid, whereas Sample Q is solid. Chemical analysis confirms that both are glycerides. Which conclusion is most appropriate?

49. A cell has normal receptor proteins and responds to an external signal, but it lacks functional GLUT-4 molecules. Which defect is most directly expected?

50. A survey detects amino acids and simple sugars in many tissues, where they participate in routine cellular processes. A coloured compound appears only in certain flower tissues and is not required for the same general processes. The most appropriate classification is: