Selected Qs - Biomolecules - NCERT Exemplar Converted to MCQs

1. Which of the following was originally obtained as a natural product from a living organism?

1.	Sulfonamide
2.	Penicillin
3.	Synthetic vitamin C
4.	Artificial growth hormone

2. The chemical bond that primarily holds amino acids together in proteins is:
1. Ester bond
2. Glycosidic bond
3. Peptide bond
4. Hydrogen bond

3. Which type of bond is responsible for linking monosaccharide units in polysaccharides?
1. Peptide bond
2. Glycosidic bond
3. Ester bond
4. Ionic bond

4. The most abundant protein in the entire biosphere is:
1. Collagen
2. RuBisCO
3. Insulin
4. Trypsin

5. The zwitterionic form of amino acids occurs due to:

1.	Only presence of amino group
2.	Only presence of carboxyl group
3.	Presence of both amino and carboxyl groups
4.	Presence of R group

6. Which polysaccharide is found in the exoskeleton of arthropods?
1. Cellulose
2. Starch
3. Chitin
4. Glycogen

7. The reducing end in a polysaccharide refers to:

1.	The left end of the chain
2.	The right end of the chain
3.	Both ends of the chain
4.	The branching points

8. Secondary metabolites in plants include all EXCEPT:
1. Alkaloids
2. Amino acids
3. Essential oils
4. Flavonoids

9. Which of the following is NOT a function of proteins in living organisms?
1. Energy storage
2. Transport of nutrients
3. Fighting infections
4. Enzymatic catalysis

10. The blue color of starch-iodine complex is due to:

1.	Oxidation of starch
2.	Formation of new chemical bonds
3.	Iodine molecules trapped in helical structure
4.	Reduction of iodine

11. Which of the following best describes lipids in living organisms?

1.	Always found as free molecules
2.	True macromolecules
3.	Found both as free molecules and in membranes
4.	Only found in cell membranes

12. The typical molecular weight range of biomolecules in the acid-soluble pool is:

1.	Above 10,000 daltons
2.	Between 18-800 daltons
3.	Between 1000-5000 daltons
4.	Below 10 daltons

13. Which of the following elements shows the most striking difference in its percentage when comparing Earth's crust vs living tissues?
1. Oxygen
2. Carbon
3. Silicon
4. Calcium

14. Amino acids can be classified as acidic, basic or neutral based on:

1.	The R group only
2.	The amino group only
3.	The number of amino and carboxyl groups
4.	The molecular weight

15. The acid-insoluble fraction of cell components contains all EXCEPT:
1. Proteins
2. Nucleic acids
3. Simple sugars
4. Membrane lipids

16. The optimum pH for maximum enzyme activity varies because:

1.	Enzymes are made of different amino acids
2.	pH affects the ionization state of amino acid functional groups
3.	pH denatures all enzymes at extreme values
4.	Enzymes work best only at neutral pH

17. Which statement about rubber is INCORRECT?

1.	It is a secondary metabolite
2.	It is a polymeric substance
3.	It is a primary metabolite
4.	It has ecological importance

18. In proteins, the sequence of amino acids represents the:
1. Tertiary structure
2. Primary structure
3. Secondary structure
4. Quaternary structure

19. The double helix structure of DNA represents its:

1.	Primary structure	2.	Secondary structure
3.	Tertiary structure	4.	Quaternary structure

20. Enzyme activity is pH dependent because:

1.	All enzymes work best at acidic pH
2.	pH affects substrate binding
3.	pH changes the ionization state of functional groups
4.	Enzymes are stable only at neutral pH

21. Which component has the highest percentage in living cells?
1. Proteins
2. Water
3. Nucleic acids
4. Lipids

22. Secondary metabolites are characterized by:

1.	Being essential for basic metabolism
2.	Having unknown functions in many cases
3.	Being present in all organisms
4.	Having small molecular weights only

23. Secondary metabolites in plants are:
1. Primary products of photosynthesis
2. Compounds essential for basic life processes
3. Compounds not directly involved in growth
4. Products of nitrogen fixation

24. Biomolecules in anhydrous conditions:
1. Show enhanced activity
2. Show normal activity
3. Show reduced activity
4. Show no biological activity

25. The classification of medicines based on their origin shows:

1.	Penicillin (natural from Penicillium), Sulfonamide (synthetic)
2.	Vitamin C (natural from citrus), Growth hormone (natural from pituitary)
3.	Natural products often require chemical modification to reduce toxicity
4.	All of the above

26. Chemical bonds characteristic of different biomolecules include:

1.	Polysaccharides linked by glycosidic bonds
2.	Proteins connected by peptide bonds
3.	Fats containing ester bonds between fatty acids and glycerol
4.	All of the above

27. Examples of biomolecule types include:

1.	Amino acid: glycine; Sugar: glucose; Nucleotide: ATP
2.	Fatty acid: palmitic acid; Protein: insulin; Polysaccharide: starch
3.	Enzyme: pepsin; Hormone: thyroxine; Vitamin: ascorbic acid
4.	All of the above

28. Oxidoreductase enzyme reactions follow the pattern:

1.	A reduced + A' oxidized → A oxidized + A' reduced
2.	Transfer of electrons from reduced substrate to oxidized substrate
3.	NAD+ and NADH represent common electron acceptor/donor pairs
4.	All of the above

29. Prosthetic groups differ from cofactors in being:

1.	Tightly bound organic compounds to enzymes
2.	Essential for enzyme activity and structure
3.	Examples include heme in hemoglobin and cytochromes
4.	All of the above

30. Glycine and alanine amino acids share common substituents:

1.	α-amino group (-NH2) and carboxyl group (-COOH)
2.	Both attached to the same α-carbon atom
3.	Differ only in the R group (H in glycine, CH₃ in alanine)
4.	All of the above

31. Polysaccharides correctly matched with their sources:

1.	Cotton fiber - cellulose; Cockroach exoskeleton - chitin
2.	Liver - glycogen; Peeled potato - starch
3.	Each represents different structural and storage functions
4.	All of the above

32. Enzyme activity pH dependence occurs because:

1.	Ionizable functional groups in amino acids change charge with pH
2.	Enzyme active site conformation depends on proper ionization state
3.	Extreme pH can denature enzyme structure
4.	All of the above

33. Rubber as a secondary metabolite demonstrates:

1.	Not directly involved in basic metabolic processes
2.	Produced by specialized plant cells for defense
3.	Polyisoprene structure with commercial importance
4.	All of the above

34. Protein structure hierarchy includes:

1.	Primary: amino acid sequence linked by peptide bonds
2.	Secondary: α-helices and β-sheets stabilized by hydrogen bonds
3.	Tertiary: 3D folding through various interactions
4.	All of the above

35. Nucleic acid secondary structure is exemplified by:

1.	DNA double helix with complementary base pairing
2.	Hydrogen bonds between adenine-thymine and guanine-cytosine
3.	Antiparallel arrangement of sugar-phosphate backbones
4.	All of the above

36. Living organisms as non-equilibrium steady-states can:

1.	Maintain organization through constant energy input
2.	Perform work by utilizing energy gradients
3.	Resist entropy increase through metabolic processes
4.	All of the above

37. Enzyme-substrate complex formation involves:

1.	Initial substrate binding to enzyme active site
2.	Conformational changes facilitating catalysis
3.	Product formation and release regenerating free enzyme
4.	All of the above

38. Enzyme classification includes six major classes:

1.	Oxidoreductases catalyzing oxidation-reduction reactions
2.	Transferases moving functional groups between molecules
3.	Hydrolases cleaving bonds using water
4.	All of the above

39. Additional enzyme classes demonstrate specificity:

1.	Lyases removing groups without hydrolysis forming double bonds
2.	Isomerases rearranging atoms within molecules
3.	Ligases joining molecules using ATP energy
4.	All of the above

40. Watson-Crick DNA model features include:

1.	Double helix with antiparallel strands
2.	Complementary base pairing through hydrogen bonds
3.	Sugar-phosphate backbone with bases pointing inward
4.	All of the above

41. Nucleotide vs nucleoside distinction involves:

1.	Nucleoside: base + sugar; Nucleotide: base + sugar + phosphate
2.	Examples: adenosine (nucleoside), ATP (nucleotide)
3.	Phosphate groups confer energy storage capacity
4.	All of the above

42. Lipid classification encompasses diverse forms:

1.	Simple lipids: fats and oils (triglycerides)
2.	Complex lipids: phospholipids and glycolipids
3.	Derived lipids: steroids and fatty acids
4.	All of the above

Fill OMR Sheet*

*If above link doesn't work, please go to test link from where you got the pdf and fill OMR from there

CLICK HERE to get FREE ACCESS for 2 days of ANY NEETprep course

Please be patient as the PDF generation may take up to a minute.

Fill OMR Sheet*