Prepare for the PPSC Analytical Chemist exam with this Biochemistry Quiz, designed to test your knowledge of key biochemical concepts. Practice with expertly crafted MCQs to boost your confidence and improve your chances of success. Stay ahead with QuaidianPoint’s top-quality exam preparation!

1. Which of the following is a monosaccharide?
   a) Sucrose
   b) Maltose
   c) Glucose
   d) Lactose
   Answer: c) Glucose
2. The simplest aldose is:
   a) Glyceraldehyde
   b) Ribose
   c) Fructose
   d) Galactose
   Answer: a) Glyceraldehyde
3. D-Glucose and D-Galactose are:
   a) Anomers
   b) Epimers
   c) Enantiomers
   d) Diastereomers
   Answer: b) Epimers
4. The anomeric carbon in glucose is:
   a) C-1
   b) C-2
   c) C-4
   d) C-5
   Answer: a) C-1
5. Which glycosidic bond is present in maltose?
   a) α(1→4)
   b) β(1→4)
   c) α(1→2)
   d) β(1→6)
   Answer: a) α(1→4)
6. Sucrose is composed of:
   a) Glucose + Glucose
   b) Glucose + Fructose
   c) Galactose + Glucose
   d) Fructose + Fructose
   Answer: b) Glucose + Fructose
7. Cellulose is a polymer of:
   a) α-D-Glucose
   b) β-D-Glucose
   c) α-D-Fructose
   d) β-D-Galactose
   Answer: b) β-D-Glucose
8. Which polysaccharide is branched?
   a) Amylose
   b) Cellulose
   c) Amylopectin
   d) Chitin
   Answer: c) Amylopectin
9. The Haworth projection of α-D-galactose shows the -OH group on the anomeric carbon:
   a) Above the ring
   b) Below the ring
   c) On the same side as CH₂OH
   d) Opposite to CH₂OH
   Answer: b) Below the ring
10. Glycoproteins are proteins with:
    a) Lipids attached
    b) Carbohydrates attached
    c) Phosphates attached
    d) Metals attached
    Answer: b) Carbohydrates attached

11. The primary structure of a protein refers to:
    a) The sequence of amino acids
    b) The α-helix formation
    c) The disulfide bonds
    d) The quaternary structure
    Answer: a) The sequence of amino acids
12. Which bond is NOT involved in stabilizing the tertiary structure of proteins?
    a) Hydrogen bonds
    b) Disulfide bonds
    c) Glycosidic bonds
    d) Hydrophobic interactions
    Answer: c) Glycosidic bonds
13. In sickle cell anemia, the mutation replaces glutamic acid with:
    a) Valine
    b) Alanine
    c) Leucine
    d) Serine
    Answer: a) Valine
14. The α-helix is stabilized primarily by:
    a) Disulfide bonds
    b) Hydrogen bonds
    c) Ionic bonds
    d) Van der Waals forces
    Answer: b) Hydrogen bonds
15. Which protein structure level involves multiple polypeptide chains?
    a) Primary
    b) Secondary
    c) Tertiary
    d) Quaternary
    Answer: d) Quaternary
16. Myoglobin binds oxygen using a:
    a) Calcium ion
    b) Heme group
    c) Zinc finger
    d) Phospholipid
    Answer: b) Heme group
17. Hemoglobin exhibits:
    a) Negative cooperativity
    b) Positive cooperativity
    c) No cooperativity
    d) Random binding
    Answer: b) Positive cooperativity
18. The β-pleated sheet is an example of:
    a) Primary structure
    b) Secondary structure
    c) Tertiary structure
    d) Quaternary structure
    Answer: b) Secondary structure
19. Chaperones assist in:
    a) Protein denaturation
    b) Protein folding
    c) Protein degradation
    d) Protein synthesis
    Answer: b) Protein folding
20. Denaturation of proteins disrupts:
    a) Primary structure
    b) Secondary and tertiary structures
    c) Only quaternary structure
    d) Covalent bonds in the backbone
    Answer: b) Secondary and tertiary structures

21. Triacylglycerols are esters of:
    a) Glycerol and fatty acids
    b) Glycerol and phosphate
    c) Sphingosine and fatty acids
    d) Cholesterol and fatty acids
    Answer: a) Glycerol and fatty acids
22. Membrane lipids are typically:
    a) Hydrophilic
    b) Amphipathic
    c) Hydrophobic
    d) Neutral
    Answer: b) Amphipathic
23. Which lipid is a major component of cell membranes?
    a) Triacylglycerol
    b) Phospholipid
    c) Steroid
    d) Wax
    Answer: b) Phospholipid
24. The fluidity of membranes is increased by:
    a) Saturated fatty acids
    b) Cholesterol
    c) Unsaturated fatty acids
    d) Long-chain fatty acids
    Answer: c) Unsaturated fatty acids
25. Lipid bilayers are permeable to:
    a) Ions
    b) Small hydrophobic molecules
    c) Large polar molecules
    d) Proteins
    Answer: b) Small hydrophobic molecules

26. The heme group in hemoglobin binds:
    a) Oxygen
    b) Carbon dioxide
    c) Nitrogen
    d) Hydrogen
    Answer: a) Oxygen
27. The prosthetic group in myoglobin is:
    a) NAD+
    b) FAD
    c) Heme
    d) Biotin
    Answer: c) Heme
28. Which technique is used to determine protein tertiary structure?
    a) NMR spectroscopy
    b) Mass spectrometry
    c) UV-Vis spectroscopy
    d) Thin-layer chromatography
    Answer: a) NMR spectroscopy
29. In the Fischer projection, the horizontal lines represent bonds:
    a) Projecting backward
    b) Projecting forward
    c) In the plane
    d) Rotating freely
    Answer: b) Projecting forward
30. The D- and L- notation in sugars is based on the configuration of:
    a) The anomeric carbon
    b) The penultimate carbon
    c) The carbonyl carbon
    d) The terminal carbon
    Answer: b) The penultimate carbon

31. Which of the following is a reducing sugar?
    a) Sucrose
    b) Lactose
    c) Trehalose
    d) Raffinose
    Answer: b) Lactose
32. The term “anomers” refers to sugars that differ in configuration at the:
    a) Penultimate carbon
    b) Anomeric carbon
    c) Terminal carbon
    d) Chiral center farthest from the carbonyl group
    Answer: b) Anomeric carbon
33. The β-1,4-glycosidic bond is found in:
    a) Amylose
    b) Cellulose
    c) Glycogen
    d) Amylopectin
    Answer: b) Cellulose
34. Which of the following is a heteropolysaccharide?
    a) Starch
    b) Cellulose
    c) Glycogen
    d) Hyaluronic acid
    Answer: d) Hyaluronic acid
35. The primary function of glycogen is:
    a) Structural support
    b) Energy storage in animals
    c) Energy storage in plants
    d) Cell signaling
    Answer: b) Energy storage in animals
36. The oxygen-binding site in myoglobin includes:
    a) A zinc ion
    b) A copper ion
    c) An iron ion
    d) A magnesium ion
    Answer: c) An iron ion
37. Which amino acid is involved in disulfide bond formation?
    a) Serine
    b) Cysteine
    c) Methionine
    d) Threonine
    Answer: b) Cysteine
38. The α-helix is a common feature of:
    a) Silk fibroin
    b) Collagen
    c) Myoglobin
    d) β-Keratin
    Answer: c) Myoglobin
39. Which of the following is NOT a force stabilizing protein tertiary structure?
    a) Hydrophobic interactions
    b) Hydrogen bonds
    c) Glycosidic bonds
    d) Disulfide bonds
    Answer: c) Glycosidic bonds
40. The quaternary structure of hemoglobin consists of:
    a) One polypeptide chain
    b) Two polypeptide chains
    c) Three polypeptide chains
    d) Four polypeptide chains
    Answer: d) Four polypeptide chains

41. Which of the following is true about the boat and chair conformations of pyranose rings?
    a) The chair form is more stable due to less steric hindrance
    b) The boat form is more stable due to hydrogen bonding
    c) Both forms are equally stable
    d) The boat form is never observed
    Answer: a) The chair form is more stable due to less steric hindrance
42. The term “proteoglycan” refers to a molecule where:
    a) Protein is the largest component by weight
    b) Carbohydrate is the largest component by weight
    c) Lipid is the largest component by weight
    d) Nucleic acid is the largest component by weight
    Answer: b) Carbohydrate is the largest component by weight
43. The binding of oxygen to hemoglobin is influenced by:
    a) pH only
    b) CO₂ only
    c) 2,3-BPG only
    d) All of the above
    Answer: d) All of the above
44. Which of the following is a characteristic of fibrous proteins?
    a) Soluble in water
    b) Compact, spherical shape
    c) Structural role
    d) Enzymatic activity
    Answer: c) Structural role
45. The term “denaturation” refers to the loss of:
    a) Primary structure
    b) Secondary and tertiary structure
    c) Covalent bonds
    d) Amino acid sequence
    Answer: b) Secondary and tertiary structure
46. Which of the following is NOT a denaturing agent?
    a) Urea
    b) Heat
    c) pH change
    d) Sucrose
    Answer: d) Sucrose
47. The heme group in hemoglobin is bound to the protein via:
    a) A histidine residue
    b) A cysteine residue
    c) A lysine residue
    d) A glutamate residue
    Answer: a) A histidine residue
48. The term “allosteric effect” refers to:
    a) Changes in protein structure at one site affecting another site
    b) The binding of small molecules to the active site
    c) The disruption of protein structure
    d) The formation of disulfide bonds
    Answer: a) Changes in protein structure at one site affecting another site
49. Which of the following is a function of glycoproteins?
    a) Energy storage
    b) Membrane function
    c) Oxygen transport
    d) DNA replication
    Answer: b) Membrane function
50. The term “mucin” refers to a glycoprotein that primarily functions as a:
    a) Structural component
    b) Lubricant
    c) Enzyme
    d) Hormone
    Answer: b) Lubricant

51. The Fischer projection of a sugar is a:
    a) 3D representation
    b) 2D representation
    c) Circular representation
    d) Spherical representation
    Answer: b) 2D representation
52. The term “axial” and “equatorial” refer to positions in the:
    a) Fischer projection
    b) Haworth projection
    c) Chair conformation
    d) Boat conformation
    Answer: c) Chair conformation
53. The term “epimer” refers to sugars that differ in configuration at:
    a) One chiral carbon
    b) The anomeric carbon
    c) All chiral carbons
    d) The carbonyl carbon
    Answer: a) One chiral carbon
54. The term “oligosaccharide” refers to a carbohydrate with:
    a) 1-10 monosaccharide units
    b) 10-100 monosaccharide units
    c) More than 100 monosaccharide units
    d) Only 1 monosaccharide unit
    Answer: a) 1-10 monosaccharide units
55. The term “homopolysaccharide” refers to a polysaccharide composed of:
    a) One type of monosaccharide
    b) Two types of monosaccharides
    c) Three types of monosaccharides
    d) No monosaccharides
    Answer: a) One type of monosaccharide
56. The term “heteropolysaccharide” refers to a polysaccharide composed of:
    a) One type of monosaccharide
    b) Two or more types of monosaccharides
    c) Only glucose units
    d) Only fructose units
    Answer: b) Two or more types of monosaccharides
57. The term “glycosidic bond” refers to a bond between:
    a) Two amino acids
    b) Two monosaccharides
    c) Two fatty acids
    d) Two nucleotides
    Answer: b) Two monosaccharides
58. The term “anomeric carbon” refers to the carbon that was part of the:
    a) Aldehyde or ketone group
    b) Hydroxyl group
    c) Methyl group
    d) Carboxyl group
    Answer: a) Aldehyde or ketone group
59. The term “Haworth projection” is used to represent the:
    a) Linear form of sugars
    b) Cyclic form of sugars
    c) Fischer projection
    d) Chair conformation
    Answer: b) Cyclic form of sugars
60. The term “pyranose” refers to a sugar with a:
    a) 5-membered ring
    b) 6-membered ring
    c) 7-membered ring
    d) Linear structure
    Answer: b) 6-membered ring