All the following statements are correct about enzymes, but one is wrong. Select the incorrect statement. 
1. Almost all enzymes are proteins
2. There are some nucleic acids which behave like enzymes and are called ribozymes
3. Enzymes obtained from thermophilic organisms retain their catalytic power even at high temperatures
up to 80-90oC
4. Ribozyme was discovered by Altman et al.

 

Subtopic:  Enzymes |
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Study the reaction given below
 
In absence of any enzyme this reaction is very slow, with 200 molecules of \(H_2CO_3\) being formed in an hour. In presence of enzyme the reaction speeds up dramatically with about 600,000 molecules formed every second. Name the enzyme which has accelerated up the reaction by 10 million times.
1. Ribozyme 
2. Carbonic anhydrase
3. Catalase 
4. Peroxidase
Subtopic:   DYNAMIC STATE OF BODY CONSTITUENTS – CONCEPT OF METABOLISM (OLD NCERT) | METABOLIC BASIS FOR LIVING (OLD NCERT) |
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Which of the following is not an example of competitive inhibition?
1. Inhibition of succinic dehydrogenase by malonate
2. Sulpha drugs used to control bacterial pathrogens
3. Inhibition of alcohol dehydrogenase by ethanol in methanol poisoning
4. Inhibition of cytochrome oxidase by cyanide
Subtopic:  Factors Affecting Enzyme Catalysis Reaction |
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Which of the following sets of coenzymes are nucleotides of vitamin niacin?
1. NAD, NADP
2. FMN, FAD
3. ATP, ADP
4. ATP, FAD
Subtopic:  Enzyme Cofactors |
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Which of the following is a cofactor for the proteolytic enzyme carboxypeptidase?
1. Zinc 
2. Copper 
3. Calcium
4. Magnesium
 
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Which of the following groups of enzymes helps in catalysing a transfer of a group ( other than hydrogen) between a pair of substrates?
1. Oxidoreductases 
2. Transferases
3. Lyases
4. Isomerases
Subtopic:  Enzymes Classification |
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Which of the following factors can influence enzyme activity?
1. High temperature 
2. pH 
3. Substrate concentration
4. All of these
 
Subtopic:  Factors Affecting Enzyme Catalysis Reaction |
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What would happen to Vmax' in presence of a competitive inhibitor?
1. Decreases
2. Increases
3. Remains the same
4. First increases then decreases
 
Subtopic:  Factors Affecting Enzyme Catalysis Reaction |
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Study the following graph of concept of activation energy given below. Select the correct option for stages labelled A to D.

 
A B C D
1 Transition State Potential energy Activation energy without enzyme Activation energy with enzyme
2 Kinetic energy Potential energy  Activation energy without enzyme Activation energy with enzyme
3 Potential energy Transition state Activation energy without enzyme Activation energy with enzyme
4 Potential energy  Transition state Activation energy without enzyme Activation energy with enzyme
Subtopic:  Enzyme Catalysis |
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Enzymes work at optimum temperature. Over a rang 0 - 40oC, what would happen to the rate of enzyme controlled reactions for every 10oC rise in temperature?
1. The rate doubles itself
2. Decreases by half
3. No effect
4. First increases then decreases
Subtopic:  Factors Affecting Enzyme Catalysis Reaction |
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