Question
The diagram represents enzyme action in a chemical reaction.
What are parts W, X and Y in this chemical reaction? 
▶️Answer/Explanation
Ans C
The correct answer is C, because :
In image, W is being broken into pieces whereas X is being intact
According to enzyme definition, it is a biological catalyst which increases rate of reaction and becomes unchanged.
So, W is substrate ; X is Enzyme and Y is Product.
Question
Which of these statements about enzymes are correct?
1 enzymes are proteins
2 enzymes are used up during chemical reactions
3 enzymes speed up metabolic reactions
A 1, 2 and 3
B 1 and 2 only
C 1 and 3 only
D 2 and 3 only
▶️Answer/Explanation
Ans C
The correct answer is C (1 and 3 only), because :
- Enzymes are proteins that function as biological catalyst
- Enzymes are involved in reaction to increase rate, but didn’t gets used up
Question
Which description of an enzyme-catalysed reaction is correct?
(A) The substrate binds to an enzyme with the same shape and a product is formed.
(B) The product binds to an enzyme with the same shape and a substrate is formed.
(C) The product binds to an enzyme with a complementary shape and a substrate is formed.
(D) The substrate binds to an enzyme with a complementary shape and a product is formed.
▶️Answer/Explanation
Ans: D
The correct answer is D, because:
Every enzyme will have an active site and substrate binds into it with complimentary shape and on reaction between them one or two products are formed.
- Both substrate and enzyme doesn’t have same shape according to Key thoery
- Products are result of substrate reaction with enzymes
- Products on forming they gets detached from enzyme
Question
Which statement about enzymes is correct?
(A) They are made of carbohydrates.
(B) Their activity is unaffected by pH.
(C) They are used up during the reaction.
(D) They have a complementary shape to their substrate.
▶️Answer/Explanation
Ans : D
The correct answer is D, because:
- Enzymes are made up of proteins
- Enzymes activity is affected by pH (Optimum pH – Best enzyme activity)
- Enzymes are not used up in reaction instead they remain same but raises reaction rate