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. Ionic bond
- B. Peptide bond
- C. Glycosidic linkage
- D. Ester bond
Explanation: Option D is correct. When an alcohol and an acid react, they form an ester linkage.
Correct answer: Ester bond- A. Fatty acids
- B. Phosphate
- C. Carboxylic acid
- D. Triacylglycerol
Explanation: Option B is correct. The head of a phospholipid molecule is polar (hydrophilic) due to the presence of a phosphate group.
Correct answer: Phosphate- A. Terpenoids
- B. Waxes
- C. Phospholipids
- D. Acylglycerols
Explanation: Option C is correct. Phospholipids are the most prominent part of cell membranes in living organisms.
Correct answer: Phospholipids- A. C18H32O16
- B. C57H10O6
- C. C300H500O250
- D. C42H45O23N17S
Explanation: Option B is correct. The molecular formula C57H10O6 represents the compound triacylglycerol, also known as a triglyceride.
Correct answer: C57H10O6- A. Waxes
- B. Phospholipids
- C. Cholesterol
- D. Acylglyecrol
Explanation: Option C is option. Yes, cholesterol is the precursor of bile acids. Bile acids are essential for the digestion and absorption of fats and…
Correct answer: Cholesterol- A. Carbohydrates
- B. Lipids
- C. Nucleic acids
- D. All of these
Explanation: Option D is correct. Carbohydrates are biomolecules. Biomolecules are organic molecules that are found in living organisms.
Correct answer: Nucleic acids- A. Lysosome
- B. Ribosomes
- C. Chromosomes
- D. Mitochondria
Explanation: Option C is correct.Nucleohistones are present in chromosomes. They are a complex of DNA and histone proteins, which are responsible for…
Correct answer: Chromosomes- A. Fatty acids
- B. Ribonucleic acid
- C. Ascorbic acid
- D. Deoxyribonucleic acid
Explanation: Option B is correct. Yes, ribonucleic acid (RNA) is the constituent of RNA molecules.
Correct answer: Ribonucleic acid- A. tRNA
- B. rRNA
- C. mRNA
- D. Primers
Explanation: Option D is correct. The type of RNA that is used to start the process of replication in a prokaryotic cell is RNA primase.
Correct answer: Primers- A. Structural and regulatory
- B. Regulatory only
- C. Structure only
- D. Transport proteins
Explanation: Option A is correct. Conjugated histone proteins are a type of conjugated protein that are found in the nucleus of eukaryotic cells.
Correct answer: Structural and regulatory- A. Glycolipids
- B. Nucleoproteins
- C. Glycoproteins
- D. All of these
Explanation: Option D is correct. Two different molecules belonging to different categories, usually combine together to form conjugated molecules.
Correct answer: All of these- A. Glycolipids
- B. Lipoproteins
- C. Glycoproteins
- D. Nucleoproteins
Explanation: Option C is correct. Yes, most of the cellular secretions are glycoproteins.
Correct answer: Glycoproteins- A. Glycolipids
- B. Nucleoprotein
- C. Glycoproteins
- D. Lipoproteins
Explanation: Option B is correct. Conjugated molecules are molecules that contain a non-protein prosthetic group, which is a group of atoms that is not…
Correct answer: Nucleoprotein- A. Carbohydrates
- B. Lipids
- C. Water
- D. Proteins
Explanation: Option D is correct. Proteins are the most abundant organic compounds in the cell, making up about 50% of the dry mass of cell.They are…
Correct answer: Proteins- A. Carbon
- B. Hydrogen
- C. Oxygen
- D. Nitrogen
Explanation: Option D is correct. All of the following elements are present in all carbohydrates except nitrogen..Nitrogen is not a common element…
Correct answer: Nitrogen- A. Enzymes
- B. Globular proteins
- C. Fibrous proteins
- D. Polypeptides
Explanation: Option D is correct. The most appropriate term that describes catalase, collagen, and hemoglobin is proteins.
Correct answer: Polypeptides- A. They are insoluble
- B. They contain carboxyl and amino groups
- C. They have a low molecular mass
- D. They possess only secondary
Explanation: Option B is correct. The property of proteins that enables them to act as pH buffers is their amphoteric nature.
Correct answer: They contain carboxyl and amino groups- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Option B is correct. In glucose, if OH group is present downward then it will be alpha carbon and if OH group is present is upward then it…
Correct answer: Option B- A. Nail
- B. Hair
- C. Plant cell wall
- D. Spider's web
Explanation: Option D is correct. Silk protein is present in spider's web. Cellulose is present in plant cell. Keratin is present in hair and nails.
Correct answer: Spider's web- A. They store a high amount of energy
- B. They are polymer of fatty acids
- C. They play important role in insulation
- D. They are mostly hydrophobic
Explanation: Option B is correct. Lipids are not polymers of fatty acids. A polymer is a molecule made up of repeating units of a smaller molecule…
Correct answer: They are polymer of fatty acids