Enzymes Test | Class 9 Biology
⚗️
🧬
🔬

Enzymes Test

Class 9th – Biology (SNC) – Chapter 7
@2025 everexams.com
Paper Date:
Time: 60 minutes
Total Marks: 50
Paper Type: Objective + Subjective
Font Size:

Multiple Choice Questions 10×1=10

1 What can happen if an enzyme is exposed to temperature that is higher than its optimal temperature?
A Enzyme activity rate will increase
B Enzyme’s shape will change, potentially reducing its activity
C Enzyme will speed up the reaction and remain stable
D Enzyme will become a substrate itself
2 What enzymes are primarily composed of:
A Carbohydrates
B Lipids
C Proteins
D Nucleic acid
3 Where do intracellular enzymes function?
A Outside the cell
B Within the cells
C In the bloodstream
D In the digestive system
4 Which enzyme is used in biological detergents to remove protein stains?
A Amylase
B Protease
C Lipase
D Lactase
5 ……… tightly bind with enzymes:
A Coenzymes
B Prosthetic groups
C Cofactors
D Ribozyme
6 What is the term used to describe the loss of an enzyme’s globular structure due to high temperature?
A Ionization
B Denaturation
C Saturation
D None of these
7 What is the optimum pH for trypsin?
A 1.5 to 2.0
B 5.0 to 6.0
C 7.0 to 8.0
D 9.0 to 10.0
8 What is the primary factor that affect the ionization of amino acids at the active site of an enzyme?
A Temperature
B Substrate concentration
C pH
D Enzyme concentration
9 Which type of inhibitor resembles the enzyme’s substrate?
A Non-competitive inhibitor
B Competitive inhibitor
C Allosteric inhibitor
D Feedback inhibitor
10 Which of the following is an example of a competitive inhibitor?
A Heavy metals
B Antibiotics
C Cancer drugs
D Vitamins

Short Answer Questions 15×2=30

I Define an enzyme. What is its role in metabolism?
II What is the effect of substrate concentration on enzyme activity?
III Which type of enzyme inhibitors inhibit the enzymes without attaching to the active site?
CI
NCI
IV Differentiate between competitive and non-competitive inhibition.
V Define metabolism?
VI What are enzymes?
VII What is enzyme specificity?

Hint: Enzymes are highly specific for their substrates

VIII What are cofactors in enzymes?
IX What is the difference between prosthetic groups and coenzymes?
X What is the active site of an enzyme?
Enzyme
Active Site
Substrate
XI Who proposed the induced fit model?
XII What is the role of the substrate in enzyme action?
XIII What is optimum temperature?
XIV What is denaturation of enzyme?
XV Where does a non-competitive inhibitor bind to the enzyme?

Detailed Answer Questions (Answer any 2) 2×5=10

1 Describe the characteristics of enzymes.

Key Characteristics:
1. Protein nature (mostly)
2. High specificity
3. Catalytic efficiency
4. Reusability
5. Sensitive to temperature and pH
6. Require cofactors in some cases

2 Explain the lock and key model of enzyme action.
Lock
Keyhole
Key
Product
Lock and Key Model: Specific substrate (key) fits into enzyme’s active site (lock)
3 Compare and contrast the effect of temperature and pH on enzyme activity.

Comparison Points:
1. Optimal ranges for both
2. Denaturation effects
3. Effect on active site
4. Reversibility of effects
5. Biological significance