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mcqs of
,
1 : Primarily, all enzymes are:
A
:
Nucleic acids
B
:
proteins
C
:
Carbohydrates
D
:
Lipids
2 : How does increasing temperature affect enzymes activity?
A
:
Increase activity to a point
B
:
Always decreases activity
C
:
Make enzymes non-functional
D
:
No effect on enzyme
3 : An enzyme works best at a pH of 7.4 placed in an acid solution with a pH of 4.0. How will this affect it?
A
:
The active side will modified reducing substrate binding
B
:
The enzyme will catalyze reaction faster due to increase H ions.
C
:
The enzyme will again additional active sites
D
:
The substrate will become inactive in an acids environment
4 : Enzymes are specific in their action because:
A
:
Their active sites fit specific substrates.
B
:
They are always proteins
C
:
They are consumed in reactions
D
:
They work only at high temperature
5 : What is true according to the induced fit model of enzyme action?
A
:
Enzyme active site change shape to bind the substrate
B
:
Substrate changes shape to bind to active site
C
:
No shape changes occur in active site or substrate
D
:
Substrate attached the enzyme at a site other that active site
6 : What is true about the optimum pH values of the following system?
A
:
Pepsin works at low pH while trypsin works at high pH
B
:
Both work at high pH
C
:
Both work at low pH
D
:
Pepsin works at high pH while trypsin works at low pH
7 : Prosthetic groups are:
A
:
Required by all enzymes
B
:
Proteins in nature
C
:
Loosely attached with enzymes
8 : What can happen if an enzyme is exposed to temperature higher than its optimal temperature?
A
:
Enzyme activity rate will increase
B
:
Enzyme shape will change potentially its activity
C
:
Enzyme will become a substrate itself
9 : Which best defines an enzyme?
A
:
A chemical that break down food
B
:
A hormone that regular metabolism
C
:
A molecule that stores energy
10 : How does competitive inhibitor affect enzyme action?
A
:
Attach with the substrate
B
:
Changes enzymes shape
C
:
Attaches and blocks the active site
D
:
Blocks the cofactors
11 : Which best defines an enzyme?
A
:
A chemical that breaks down food
B
:
A hormone that regular metabolism
C
:
A protein that speed up reaction
D
:
A molecular that stores energy
12 : Which of the following is an example of anabolism?
A
:
Cellular respiration
B
:
Lipolysis
C
:
Protein synthesis
D
:
Glycolysis
13 : The part of enzyme molecule involved in catalysis is called:
A
:
Active site
B
:
Co-factor
C
:
Co-enzyme
D
:
Prosthetic group
14 : Structurally enzymes are made of:
A
:
Minerals
B
:
Amino acids
C
:
Vitamins
D
:
Fats
15 : In which medium enzyme trypsin works?
A
:
Alkaline
B
:
Acidic
C
:
Neutral
D
:
Slight basic
16 : Enzyme used for the removal of protein stains from clothes is:
A
:
Protease
B
:
Lipase
C
:
Amylase
D
:
Pepsin
17 : When organic co-factor are tightly bound to enzyme, they are called:
A
:
Coenzyme
B
:
Apoenzyme
C
:
Cofactor
D
:
Prosthetic group
18 : One important co-enzyme is:
A
:
Amylase
B
:
Sodium ion
C
:
Glucose
D
:
Folic acid
19 : Enzyme pepsin works in:
A
:
Mouth
B
:
Intestine
C
:
Oesophagus
D
:
Stomach
20 : The Enzyme which acts only on Lipids is:
A
:
Lipase
B
:
Amylase
C
:
Pepsin
D
:
Protease
21 : What is true about co-factors?
A
:
Break hydrogen bonds in protein
B
:
Help facilitate Enzyme activity
C
:
Inhibit enzyme function
D
:
Replace enzymes in reactions
22 : Example of vitamin is:
A
:
Riboflavin
B
:
Glucose
C
:
Fatty acid
D
:
Glycerin
23 : Protein is digested by:
A
:
Lipase
B
:
Amylase
C
:
Protease
D
:
Nuclease
24 : All biochemical reactions occurring in living organisms necessary for life are called:
A
:
Metabolism
B
:
Anabolism
C
:
Catabolism
D
:
Mutualism
25 : The catalytic region of the enzyme is called:
A
:
Co-enzyme
B
:
Inhibitor
C
:
Activator
D
:
Active site
26 : To what category of molecules do enzymes belong?
A
:
Carbohydrates
B
:
Proteins
C
:
Lipids
D
:
Nucleic acids
27 : Who first used the term 'Enzyme'?
A
:
Ibn-e-Nafees
B
:
Emil Fischer
C
:
Winhelm Kuhne
D
:
Louis Pasteur
28 : Chemically enzymes are:
A
:
Protein
B
:
Carbohydrates
C
:
Lipids
D
:
Fats
29 : Lock and Key model was proposed in:
A
:
1824
B
:
1924
C
:
1994
D
:
1894
30 : Temperature for the maximum working speed of human enzyme is:
A
:
30°C
B
:
37°C
C
:
35°C
D
:
32°C
31 : Enzyme involved in breakdown of Starch is:
A
:
Lipase
B
:
Protease
C
:
Amylase
D
:
Pepsin
32 : Biological detergent is:
A
:
Protease
B
:
Pepsin
C
:
Riboflavin
D
:
Thiamine
33 : Metabolism is derived from Greek word meaning:
A
:
Division
B
:
Change
C
:
Deduction
D
:
Matter
34 : At what pH does pepsin, an enzyme in the stomach, work best?
A
:
pH 1.5 to 2.0
B
:
pH 7 to 8
C
:
pH 3 to 4
D
:
pH 10 to 11
35 : Which of the following vitamins work as coenzyme?
A
:
Vitamin B
B
:
Vitamin D
C
:
Vitamin C
D
:
Riboflavin
36 : What happens when an enzyme is exposed to temperatures above its optimum?
A
:
The enzyme becomes more efficient
B
:
The enzyme's structure is unchanged
C
:
The enzyme undergoes denaturation
D
:
The enzyme becomes inactive
37 : What is true about Enzymes:
A
:
They make biological reactions to proceed spontaneously
B
:
They lower the activation energy of a reaction
C
:
They are not very specific in their choice of substrates
D
:
They are needed in large quantities
38 : The name of enzyme used in dish washing is:
A
:
Protease
B
:
Lipase
C
:
Amylase
D
:
Pepsin
39 : Protease acts only on:
A
:
Acids
B
:
Carbohydrates
C
:
Protein
D
:
Lipids
40 : Which process is an example of catabolism?
A
:
Photosynthesis
B
:
Protein synthesis
C
:
Lipolysis
D
:
DNA replication
41 : Enzyme Amylase is used in:
A
:
Cloth washing
B
:
Dish washing
C
:
Clouring
D
:
Saponification
42 : When was induced fit model presented?
A
:
1858
B
:
1956
C
:
1963
D
:
1958
43 : In all biochemical reactions, the synthesis of large compounds is involved in:
A
:
Catabolism
B
:
Anabolism
C
:
Respiration
D
:
Transpiration
44 : What is the optimum temperature for most human enzymes?
A
:
25°C
B
:
37°C
C
:
50°C
D
:
100°C
45 : Who proposed the induced fit model of enzyme action?
A
:
Emil Fischer
B
:
Daniel Koshland
C
:
Ibn-e-Nafees
D
:
Jabir Bin Hayan
46 : What happens to enzyme activity when the pH moves away from its optimum?
A
:
It increases significantly
B
:
It stays the same
C
:
It decreases or is blocked completely
D
:
It becomes irreversible
47 : In metabolism, works as catalyst:
A
:
Enzyme
B
:
Vitamins
C
:
Protein
D
:
Lipids
48 : What is the main energy source used in photosynthesis?
A
:
ATP
B
:
Glucose
C
:
Sunlight
D
:
Carbon dioxide
49 : Lock and Key Model was proposed by:
A
:
Emil Fischer
B
:
Daniel Koshland
C
:
Winhelm
D
:
Calvin
50 : At high substrate concentrations, what limits the rate of enzyme reactions?
A
:
Lack of substrate
B
:
Low temperature
C
:
Saturation of active sites
D
:
Increased enzyme production
51 : How do competitive inhibitors affect enzyme activity?
A
:
By changing the enzyme's shape
B
:
By attaching to the enzyme's active site
C
:
By increasing the rate of reaction
D
:
By attaching to the enzyme's cofactor
52 : Which of the following is an example of a competitive inhibitor?
A
:
Mercury
B
:
Antibiotics
C
:
Biotin
D
:
Nucleotides
53 : What is enzyme inhibition?
A
:
The increase in enzyme activity
B
:
The decrease in enzyme activity
C
:
The alteration of enzyme structure
D
:
The formation of enzyme-substrate complexes
54 : What occurs when the enzyme is denatured?
A
:
It speeds up the reaction
B
:
It loses its globular structure and becomes inactive
C
:
It becomes more efficient
D
:
It becomes more rigid
55 : Which of the following is an example of a non-competitive inhibitor?
A
:
Antibiotics
B
:
Heavy metals like mercury
C
:
Glucose
D
:
Oxygen
56 : Alcohol is prepared by:
A
:
Yeast
B
:
Algae
C
:
Onion
D
:
Pepper
57 : Which of the following factors affects enzyme activity?
A
:
Temperature
B
:
pH
C
:
Substrate concentration
D
:
All of the above
58 : Trypsin enzyme shows its activity at:
A
:
Medium pH
B
:
High pH
C
:
Low pH
D
:
Acidic pH
59 : Which enzyme works best in an alkaline medium with a pH of 7 to 8?
A
:
Pepsin
B
:
Amylase
C
:
Trypsin
D
:
Lipase
60 : The term metabolism is derived from which language?
A
:
English
B
:
Italian
C
:
Greek
D
:
Roman
61 : Enzyme Lipase acts only on:
A
:
Lipids
B
:
Protein
C
:
Carbohydrate
D
:
Hormones
Biology 9th MCQs || Ilam Ghar
Chapter 7 : Enzymes
Biology 9th
