Questions on Biochemical Reactions
20 multiple choice questions on Biochemical Reactions, suitable for high school or introductory college biology. The correct answers are provided at the end.
Multiple Choice Questions: Biochemical Reactions
1. What are biochemical reactions?
A) Reactions between acids and bases
B) Reactions that occur only in labs
C) Chemical reactions that occur in living organisms
D) Reactions that form crystals
2. Which of the following molecules speeds up biochemical reactions?
A) Lipids
B) Carbohydrates
C) Enzymes
D) DNA
3. The substance an enzyme acts upon is called the:
A) Product
B) Substrate
C) Catalyst
D) Reactant
4. What is the energy needed to start a chemical reaction?
A) Activation energy
B) Thermal energy
C) Kinetic energy
D) Potential energy
5. Biochemical reactions that release energy are called:
A) Endergonic
B) Exergonic
C) Static
D) Kinetic
6. In which part of the enzyme does the substrate fit?
A) Active site
B) Reaction zone
C) Binding pocket
D) Ribosome
7. Which factor does NOT affect the rate of enzyme activity?
A) Temperature
B) pH
C) Light intensity
D) Substrate concentration
8. What happens to an enzyme when it is denatured?
A) It becomes more active
B) It changes shape and loses function
C) It breaks down into sugars
D) It replicates itself
9. What is a product in a biochemical reaction?
A) The molecule that speeds up the reaction
B) The energy produced
C) The result of the chemical reaction
D) The molecule that enters the enzyme
10. Which of the following is an example of a catabolic reaction?
A) Photosynthesis
B) Protein synthesis
C) DNA replication
D) Cellular respiration
11. Which of the following is an example of an anabolic reaction?
A) Digestion
B) Glycolysis
C) Protein synthesis
D) Fermentation
12. Enzymes are typically composed of:
A) Lipids
B) Proteins
C) Carbohydrates
D) Nucleic acids
13. Which term describes the specific shape of an enzyme that allows it to function?
A) Lock-and-key model
B) Enzyme affinity
C) Reaction quotient
D) Base pairing
14. When an enzyme is used in a reaction, it:
A) Is used up
B) Becomes a reactant
C) Remains unchanged
D) Becomes a product
15. Biochemical reactions in cells are usually helped by:
A) Hormones
B) Vitamins
C) Enzymes
D) RNA
16. The reactants in a biochemical reaction are also called:
A) Products
B) Enzymes
C) Substrates
D) Cofactors
17. Which statement is true about enzymes and temperature?
A) All enzymes work best at high temperatures
B) Enzyme activity decreases at low temperatures
C) Enzymes are not affected by temperature
D) Enzymes work better in freezing conditions
18. Which condition will most likely cause an enzyme to stop working?
A) Optimal pH
B) Warm temperature
C) Extremely high temperature
D) Substrate availability
19. Which term refers to a biological catalyst?
A) Carbohydrate
B) Hormone
C) Enzyme
D) Vitamin
20. What is the role of water in many biochemical reactions?
A) Acts as a substrate only
B) Always acts as a catalyst
C) Often used to break down or build molecules
D) Inhibits enzyme activity
Answer Key
1. C) Chemical reactions that occur in living organisms
2. C) Enzymes
3. B) Substrate
4. A) Activation energy
5. B) Exergonic
6. A) Active site
7. C) Light intensity
8. B) It changes shape and loses function
9. C) The result of the chemical reaction
10. D) Cellular respiration
11. C) Protein synthesis
12. B) Proteins
13. A) Lock-and-key model
14. C) Remains unchanged
15. C) Enzymes
16. C) Substrates
17. B) Enzyme activity decreases at low temperatures
18. C) Extremely high temperature
19. C) Enzyme
20. C) Often used to break down or build molecules
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