arrow_backBack to Study Resources

Quiz Chapter 4: Chemical Composition in Cells

10 questions · Form 4 Biology Bab 4: Chemical Composition in Cells

10 questions · plays in fullscreen

Full Question List & Answer Key

Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.

1. Which of the following disaccharides is classified as a NON-REDUCING sugar?

  1. A. Maltose
  2. B. Sucrose
  3. C. Lactose
  4. D. Cellobiose
Show answer

Answer: B

Sucrose is the only common disaccharide that does not reduce Benedict's solution because its reducing aldehyde and ketone groups are involved in the glycosidic bond.

2. Which of the following organic compounds is composed of carbon, hydrogen, oxygen, nitrogen, and sulfur?

  1. A. Carbohydrate
  2. B. Lipid
  3. C. Protein
  4. D. Nucleic acid
Show answer

Answer: C

Proteins contain amino acids, some of which (like cysteine and methionine) possess sulfur atoms.

3. Which organic molecule forms the structural cuticle layer on the epidermis of leaves to minimize transpiration water loss?

  1. A. Phospholipid
  2. B. Wax
  3. C. Steroid
  4. D. Cellulose
Show answer

Answer: B

Waxes are hydrophobic lipids that provide a waterproof barrier on plant leaves and fruits.

4. Which characteristic explains why lipids make effective energy storage molecules compared to carbohydrates?

  1. A. Lipids release twice as much energy per gram due to higher carbon and hydrogen ratios.
  2. B. Lipids are completely soluble in cellular cytoplasm.
  3. C. Lipids digest faster than simple sugars.
  4. D. Lipids contain nitrogen and phosphorus atoms.
Show answer

Answer: A

Lipids yield approximately 38 kJ/g of energy—more than double the ~17 kJ/g produced by carbohydrates—due to higher proportions of C-H bonds.

5. Why does water have a high specific heat capacity (4.2 kJ kg-1 °C-1?

  1. A. Oxygen and hydrogen atoms share electrons equally.
  2. B. Energy is required to break numerous hydrogen bonds before temperature rises.
  3. C. Water molecules are linked by strong covalent ester bonds.
  4. D. Water contains heavy mineral salts.
Show answer

Answer: B

A large amount of thermal energy is absorbed to break hydrogen bonds between water molecules before kinetic energy and temperature increase.

6. Why is cellulose impossible for humans to digest, yet essential in the human diet?

  1. A. Humans lack the cellulase enzyme; cellulose acts as dietary fiber to prevent constipation.
  2. B. Cellulose poisons digestive enzymes.
  3. C. Cellulose dissolves instantly in stomach acid without absorption.
  4. D. Cellulose is absorbed directly without digestion.
Show answer

Answer: A

Humans do not produce cellulase to digest beta-glycosidic bonds in cellulose, but it provides essential dietary roughage to stimulate peristalsis.

7. Which bond stabilizes the alpha-helix and beta-pleated sheet in the secondary structure of proteins?

  1. A. Peptide bond
  2. B. Hydrogen bond
  3. C. Disulfide bridge
  4. D. Ionic bond
Show answer

Answer: B

Hydrogen bonds forming between the C=O and N-H groups of the polypeptide backbone stabilize secondary protein structures.

8. What forms the structural backbone of a single polynucleotide strand in DNA?

  1. A. Alternating hydrogen and peptide bonds
  2. B. Complementary nitrogenous base pairs
  3. C. Alternating phosphate groups and pentose sugars linked by phosphodiester bonds
  4. D. Fatty acid chains bound to glycerol
Show answer

Answer: C

The DNA strand backbone consists of repeating sugar-phosphate units linked covalently via phosphodiester bonds.

9. What type of bond joins two monosaccharide molecules together during a condensation reaction?

  1. A. Peptide bond
  2. B. Phosphodiester bond
  3. C. Glycosidic bond
  4. D. Hydrogen bond
Show answer

Answer: C

A covalent glycosidic bond forms between hydroxyl groups of two monosaccharides during condensation.

10. Hemoglobin consists of four interconnected polypeptide subunits. What structural level of protein organization does this represent?

  1. A. Primary structure
  2. B. Secondary structure
  3. C. Tertiary structure
  4. D. Quaternary structure
Show answer

Answer: D

Quaternary structure describes proteins containing two or more polypeptide chains joined into a single functional unit.

Sponsored