Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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- A. Insoluble in water and soluble in fat solvents
- B. High energy content
- C. Structural component of the cell membrane
- D. All of these
Explanation: The correct answer is "Option: D: All of these." Lipids are diverse molecules that share several key properties: they are insoluble in…
Correct answer: All of these- A. Ether
- B. Water
- C. Alcohol
- D. All solvents
Explanation: Lipids are primarily nonpolar molecules, which makes them soluble in nonpolar solvents, such as ether.
Correct answer: Ether- A. 2 glycerol, 2 fatty acids & 1 phosphoric acid
- B. 2 glycerol, 1 fatty acids & 1 phosphoric acid
- C. 1 glycerol, 2 fatty acids & 1 phosphoric acid
- D. 2 glycerol, 1 fatty acids & 2 phosphoric acid
Explanation: Phosphatidic acid is a fundamental structure in the formation of phospholipids, which are essential components of cell membranes.
Correct answer: 1 glycerol, 2 fatty acids & 1 phosphoric acid- A. Hydrophilic
- B. Hydrophobic
- C. Neutral
- D. Amphipathic
Explanation: Lipids are insoluble in water because they are hydrophobic. Hydrophobic substances do not interact well with polar water molecules.
Correct answer: Hydrophobic1525. Sucrose is present in:
- A. Sugarcane
- B. Milk
- C. Almonds
- D. None
Explanation: Sucrose is a disaccharide composed of glucose and fructose. It is most abundantly found in sugarcane and sugar beet, from which it is…
Correct answer: Sugarcane- A. Phospholipid
- B. Polysaccharides
- C. Carbohydrates
- D. Both B and C
Explanation: Glycogen is a complex carbohydrate that serves as a form of energy storage in animals and is classified as a polysaccharide because it…
Correct answer: Both B and C- A. Fatty acids and Water
- B. Fatty acids and Alcohols
- C. Fatty acids and Glucose
- D. Fatty acids and Phosphates
Explanation: Acylglycerols like fats and oils are esters formed by condensation reaction between fatty acids and alcohols.
Correct answer: Fatty acids and Alcohols- A. Quaternary structure
- B. Secondary structure
- C. Tertiary structure
- D. Primary structure
Explanation: The regular coiling or zigzagging of a polypeptide chain through hydrogen bonding between the amino acid residues forms its secondary…
Correct answer: Secondary structure- A. Carboxyl acid
- B. Phenol
- C. Water
- D. Alcohol
Explanation: The explanation for this question will be added soon!
Correct answer: Carboxyl acid1530. The most abundant protein in animals forming 25%-35% of body protein is which type of protein?
- A. Simple proteins
- B. Conjugated proteins
- C. Derived proteins
- D. None
Explanation: The most abundant protein in animals, forming 25%-35% of body protein, is a type of conjugated protein known as hemoglobin.
Correct answer: Conjugated proteins- A. Amylase
- B. Lipase
- C. Maltase
- D. Protease
Explanation: Lipase breaks down fats( triglycerides) into their constituent fatty acids and glycerol
Correct answer: Lipase- A. Acid halides
- B. Binary compounds
- C. Ester
- D. Alkanes
Explanation: Explanation for this question will be added soon!
Correct answer: Ester- A. Animals
- B. Plants
- C. Human being
- D. None
Explanation: Explanation for this question will be added soon!
Correct answer: Animals- A. Glycosidic bond
- B. Hydrogen bond
- C. Peptide bond
- D. Disulfide bond
Explanation: The correct answer is the glycosidic bond. This bond is a covalent linkage specifically formed between two monosaccharides, resulting in…
Correct answer: Glycosidic bond- A. 3
- B. 6
- C. 9
- D. 12
Explanation: The correct answer is Option C: 9. The water-soluble vitamins include the B-complex vitamins and Vitamin C.
Correct answer: 9- A. Fatty acids
- B. Ribulose
- C. Ascorbic acid
- D. Deoxyribonucleic acid
- E. Ribonucleic acid
Explanation: RNA (ribonucleic acid) is a type of nucleic acid that is involved in the process of protein synthesis.
Correct answer: Ribonucleic acid- A. Hypertonic
- B. Hypotonic
- C. Isotonic
- D. Heterotonic
Explanation: In isotonic conditions, water potential is the same as in cell sap, solute concentration is also the same as in cell sap.
Correct answer: Isotonic- A. Less water leaves the cell than enters it, so the cell shrinks.
- B. More water enters the cell than leaves it, so the cell swells and bursts.
- C. Water enters the cells and none leaves it, so the cell swells and bursts.
- D. Water enters the cell and more leaves it, so the cell shrinks.
Explanation: b) More water enters the cell than leaves it, so the cell swells and bursts:This option is partially correct.
Correct answer: More water enters the cell than leaves it, so the cell swells and bursts.- A. Surface tension
- B. Polarity
- C. Heat capacity
- D. Viscosity
Explanation: Water is a good solvent because of its polarity and ability to form hydrogen bonds.
Correct answer: Polarity- A. 7.45 to 7.55
- B. 7.35 to 7.45
- C. 7.15 to 7.25
- D. 7.25 to 7.35
Explanation: Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45. Usually the body maintains the pH of blood close to 7.40.
Correct answer: 7.35 to 7.45