Biomolecules Mock Test – Class 11 Biology

1. Evaluate the following statements about the illustrated glycogen arrangement.
I. It is a branched glucose polymer.
II. Its labelled right end is the reducing end.
III. Its labelled left end is the non-reducing end.
IV. Its branching establishes that the monomer is fructose.

2. In a pathway, catalyses oxidation of A with simultaneous reduction of X. then moves group G from the oxidised A molecule to B. If the oxidised form of A accumulates while B-G formation decreases, which enzyme is most likely impaired?

3. 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?

4. A bacterial enzyme normally binds succinate. A structurally similar molecule binds at the same site but is not converted, and bacterial product formation decreases. The molecule is identified as malonate. Which mechanism is operating?

5. Two cell preparations have the compositions shown below.

Which comparison is supported?

6. Consider the following statements about complex lipids in neural tissue.
I. Neural tissue may contain lipids more complex than simple fatty acids, glycerides and lecithin.
II. All such complex lipids need not have an identical structure.
III. Neural-tissue occurrence alone cannot establish a precise lipid subclass.
IV. Every complex neural lipid is necessarily lecithin.

7. What is the uncatalysed formation rate of in molecules per second if molecules form in one hour?

8. Succinic dehydrogenase is tested under four conditions.

Which interpretation best fits the complete data?

9. Match each feature of enzyme classification with its description. A Column II entry is used once.

10. A text-described filtration setup has Region P as the clear liquid collected below a cotton filter and Region Q as the material remaining on the cotton after a trichloroacetic-acid tissue slurry is poured through it. Which labelling is appropriate?

11. A report listing , , phosphate and sulphate is closer to ______ analysis than to elemental analysis, since it identifies chemical forms rather than only element names.

12. A monomeric protein retains most of its local -helices and -sheets after treatment, but these elements no longer pack into the original compact shape. Its biological activity falls sharply. The level most directly disrupted is:

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

14. Use the two molecular descriptions below.
Structure P contains a carboxyl group attached to a hydrocarbon chain with no bond. Structure Q has the same general plan but contains two bonds. How should P and Q be classified?

15. A learner assumes that every visually exposed tip in a branched glycogen drawing must be a reducing end. The supplied labels instead identify a right reducing end and left non-reducing ends. What correction is required?

16. 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.

17. A polypeptide has the sequence from its N-terminal end to its C-terminal end. An enzyme removes only the N-terminal alanine without cleaving any other bond. What are the new terminal residues?

18. Two equal tissue samples are treated with the same volume of trichloroacetic acid. Sample P is thoroughly ground before filtration, whereas Sample Q is filtered without grinding. Which result is most likely?

19. Match each substance with the products expected after complete breakdown. A Column II entry is used once.

20. A process has a rate of at . Using the stated rule of thumb, what rate is predicted at , assuming the process remains otherwise unaffected?

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

22. In the sequence , how should B be described?

23. Consider the following statements about named nucleosides and nucleotides.
I. Adenosine is a nucleoside.
II. Guanylic acid is a nucleoside.
III. Thymidine is a nucleoside.
IV. Cytidylic acid is a nucleotide.

24. Assertion: Every organic substance recovered in the acid-insoluble fraction is a true biomacromolecular polymer.
Reason: Lipids may enter this fraction through association with disrupted membrane material even though individual lipid molecules are generally small and non-polymeric.

25. A healthy person consumes a balanced diet supplying all essential amino acids but very little of several non-essential amino acids. Which outcome is most consistent with the classification?

26. Four substances recovered from living tissue are described below.

Which pair consists of true polymeric biomacromolecules built from units that can occur as small cellular molecules?

27. Three analytical records are obtained from living tissue.

How should the records be classified?

28. An enzyme shows the activity pattern below.

Which conclusion best fits the data?

29. Assertion: Water is an essential constituent of living tissue but is not classified as a biomolecule under the carbon-compound definition.
Reason: The term biomolecule is applied to carbon compounds obtained from living tissue, whereas water is an inorganic compound.

30. An unknown compound is found in many cell types and is consistently linked with an ordinary physiological process. A second compound occurs only in selected plant and fungal tissues. How should their relationship be interpreted?

31. A neutral amino-acid model initially contains one amino group and one carboxyl group. Its -group is modified so that it gains one additional carboxyl group without gaining another amino group. Its classification will most likely change to:

32. A molecule from the adenine–guanine–cytosine–uracil–thymine set consists only of its nitrogen-containing heterocyclic structure. It has neither an attached sugar nor phosphate. The molecule should be classified as:

33. Consider the following statements about optimum pH and optimum temperature.
I. Each optimum corresponds to the condition giving maximum measured enzyme activity.
II. Activity commonly decreases on either side of an optimum.
III. All enzymes possess identical optimum values.
IV. Peak-shaped activity curves can be obtained when one condition is varied while others are controlled.

34. 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?

35. Let represent micromolecules, the acid-insoluble fraction, true polymeric biomacromolecules and individual membrane lipids recovered with membrane fragments. Which relation best represents the lipid exception?

36. Uridine undergoes esterification with a phosphate group while its base–sugar connection remains unchanged. The product formed is:

37. Examine the molecular records below.

Which records are internally consistent?

38. 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.

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

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

41. Two polypeptides have the compositions shown below.

Which comparison is accurate?

42. An amino acid is identified as aromatic from the structure of its -group. What can be concluded about its acidic, basic or neutral classification from that observation alone?

43. 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?

44. To compare whether several activity losses are reversible, a researcher plans the following stages.
P. Measure control activity under favourable conditions.
Q. Expose separate enzyme samples to one changed factor each.
R. Restore the original temperature or pH, remove the added chemical, or replace the removed cofactor.
S. Re-measure activity and compare recovery with the control.
What is the correct order?

45. Equal amounts of starch and cellulose are placed in separate tubes and treated with the same iodine solution. The starch tube becomes blue, while the cellulose tube does not. What is the strongest structural inference?

46. A pathway contains the reactions shown below.



Which classification of , and is correct?

47. Assertion: A competitive inhibitor can reduce productive enzyme-substrate complex formation.
Reason: Competitive inhibition occurs through permanent hydrolysis of every peptide bond in the enzyme.

48. One amino acid in a functional protein is replaced by a different amino acid. The altered side chain prevents the polypeptide from acquiring its normal compact fold. Which conclusion best integrates the changes?

49. An enzyme is heated and loses its compact shape. Its peptide bonds remain intact, but the substrate no longer fits into the original pocket and catalytic activity falls. What is the strongest inference?

50. Assertion: Dehydrogenases are classified as transferases since they move any group from one substrate to another.
Reason: Dehydrogenases belong to oxidoreductases and catalyse oxidation-reduction between paired substrates.