Biomolecules are the building blocks of life, encompassing a range of organic molecules that are essential for the structure and function of living organisms. Let’s explore the fascinating world of biomolecules with these 25 Multiple Choice Questions (MCQs) tailored for beginners. Each question comes with an answer and a concise explanation to help you understand the core concepts better. So, let’s get started!
1. Which of the following is considered a monomer of proteins?
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Explanation:
Amino acids are the building blocks (monomers) of proteins. They combine to form polymers called polypeptides, which fold into functional proteins.
2. What is the primary function of carbohydrates in the body?
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Explanation:
Carbohydrates primarily serve as a quick source of energy for the body, especially for the brain and muscles.
3. Which biomolecule is responsible for storing genetic information?
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Explanation:
DNA (Deoxyribonucleic Acid) stores genetic information in cells and is responsible for hereditary traits.
4. What is the main component of cell membranes?
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Explanation:
Phospholipids form the basic structure of cell membranes, creating a lipid bilayer that separates the interior of the cell from the external environment.
5. Which of the following is NOT a function of proteins?
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Explanation:
Proteins have various functions including catalysis, structural support, and transport, but they do not store genetic information.
6. What is the function of enzymes?
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Explanation:
Enzymes are proteins that act as biological catalysts to speed up biochemical reactions in the body.
7. Which of the following biomolecules is hydrophobic?
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Explanation:
Lipids are hydrophobic, meaning they do not mix with water. This property is essential for the formation of cell membranes.
8. What is the function of RNA?
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Explanation:
RNA (Ribonucleic Acid) plays a crucial role in protein synthesis, acting as a messenger and a builder of proteins.
9. Which type of carbohydrate is cellulose?
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Explanation:
Cellulose is a polysaccharide, consisting of a long chain of glucose molecules, and it provides structural support to plant cell walls.
10. Which of the following bases is found in RNA but not in DNA?
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Explanation:
Uracil is a nitrogenous base found in RNA, replacing thymine, which is present in DNA.
11. Which type of lipid is cholesterol?
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Explanation:
Cholesterol is a type of steroid lipid, important for cell membrane structure and the synthesis of hormones.
12. What is the primary structure of a protein determined by?
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Explanation:
The primary structure of a protein is determined by the sequence of amino acids in its polypeptide chain.
13. Which of the following biomolecules can act as hormones?
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Explanation:
Both proteins and lipids can act as hormones, serving as chemical messengers in the body.
14. What is glycogen?
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Explanation:
Glycogen is a polysaccharide carbohydrate, serving as the primary storage form of glucose in animals.
15. Which of the following is NOT a nucleotide in DNA?
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Explanation:
Ribose is a sugar, not a nucleotide. The nucleotides in DNA are Adenine, Cytosine, Guanine, and Thymine.
16. Which of the following molecules acts as an energy currency for cells?
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Explanation:
ATP (Adenosine Triphosphate) acts as the energy currency of the cell, providing energy for various cellular functions.
17. Which of the following is a characteristic of saturated fats?
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Explanation:
Saturated fats have no double bonds between carbon atoms, making them solid at room temperature.
18. Which type of RNA carries amino acids to the ribosome during protein synthesis?
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Explanation:
Transfer RNA (tRNA) carries amino acids to the ribosome during protein synthesis.
19. Which biomolecule serves as a catalyst in metabolic reactions to lower the activation energy?
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Explanation:
Enzymes are proteins that act as catalysts in metabolic reactions, lowering the activation energy required for the reaction to proceed.
20. What is the function of a nucleotide in DNA?
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Explanation:
Nucleotides in DNA form the genetic code, carrying genetic information necessary for the synthesis of proteins and other cellular activities.
21. Which carbohydrate is known as table sugar?
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Explanation:
Sucrose is commonly known as table sugar, consisting of one glucose and one fructose molecule.
22. Which type of bond is formed between amino acids to make a protein?
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Explanation:
A peptide bond is a covalent bond formed between the amino group of one amino acid and the carboxyl group of another, linking amino acids to form a protein.
23. What is the function of lipids in the human body?
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Explanation:
Lipids function mainly as a long-term energy storage and insulator in the human body, in addition to other roles like forming cell membranes.
24. Which type of RNA is responsible for bringing the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm?
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Explanation:
Messenger RNA (mRNA) is responsible for carrying the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis.
25. What is the building block of a nucleic acid?
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Explanation:
Nucleotides are the building blocks of nucleic acids, consisting of a phosphate group, a sugar, and a nitrogenous base.