Quiz on Enzymes
Enzymes are biological catalysts made of proteins that speed up chemical reactions in living organisms without being consumed. Each enzyme acts on a specific substrate and converts it into a product. Enzymes lower the activation energy required for reactions. Their activity depends on temperature, pH, and concentration. The region where the substrate binds is called the active site. Examples include amylase, lipase, pepsin, and DNA polymerase. Enzymes play a vital role in digestion, metabolism, and cellular regulation.
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MCQ Questions on Quiz on Enzymes
Q. What are enzymes made of?
A. Carbohydrates
B. Proteins
C. Lipids
D. Nucleic acids
Correct: Option (B)
Explanation: Most enzymes are proteins that act as biological catalysts.
Q. Which statement best describes the function of enzymes?
A. They slow down chemical reactions
B. They increase the activation energy of reactions
C. They speed up chemical reactions without being used up
D. They are used up during reactions
Correct: Option (C)
Explanation: Enzymes accelerate reactions by lowering activation energy and remain unchanged afterward.
Q. What is the region on an enzyme where the substrate binds called?
A. Active site
B. Binding site
C. Catalytic pocket
D. Reaction zone
Correct: Option (A)
Explanation: The active site is the specific region of the enzyme that binds to the substrate.
Q. Enzyme activity is affected by:
A. Temperature
B. pH
C. Substrate concentration
D. All of the above
Correct: Option (D)
Explanation: Enzymes are sensitive to environmental conditions like temperature, pH, and substrate levels.
Q. Which enzyme breaks down starch into sugar?
A. Pepsin
B. Lipase
C. Amylase
D. Trypsin
Correct: Option (C)
Explanation: Amylase breaks down starch into maltose and other simple sugars.
Q. Which of the following is a digestive enzyme?
A. Hemoglobin
B. Keratin
C. Pepsin
D. Collagen
Correct: Option (C)
Explanation: Pepsin is a digestive enzyme in the stomach that breaks down proteins into peptides.
Q. What happens to enzymes at very high temperatures?
A. They become more active
B. They denature and lose function
C. They change substrate type
D. They multiply
Correct: Option (B)
Explanation: High temperatures disrupt enzyme structure, causing denaturation and loss of activity.
Q. Which of the following best defines a catalyst?
A. A substance that slows down reactions
B. A substance that speeds up reactions without being consumed
C. A substance that changes the products
D. A substance that increases activation energy
Correct: Option (B)
Explanation: Catalysts, including enzymes, speed up reactions without undergoing permanent change.
Q. Which of the following enzymes helps in fat digestion?
A. Amylase
B. Lipase
C. Pepsin
D. Trypsin
Correct: Option (B)
Explanation: Lipase breaks down fats into fatty acids and glycerol.
Q. The enzyme that helps in DNA replication is:
A. Amylase
B. Pepsin
C. DNA polymerase
D. Lipase
Correct: Option (C)
Explanation: DNA polymerase synthesizes new strands of DNA during replication.