Enzymes are biocatalysts. They catalyze biochemical reactions. In general, they reduce the activation energy of reactions. Many physicochemical processes are enzyme-mediated. Which of the following reactions is not enzyme-mediated in the biological system?
1. Dissolving CO2 in water
2. Untwining the two strands of DNA
3. Hydrolysis of sucrose
4. Formation of peptide bond
Which of the following statements regarding enzyme inhibition is correct:
1. | Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein |
2. | Non-competitive inhibitors often bind to the enzyme irreversibly |
3. | Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme |
4. | Non-competitive inhibition of an enzyme can be overcome by adding large amounts of substrate |
Role of enzyme in reactions is to:
1. Decrease activation energy
2. Increase activation energy
3. Act as an inorganic catalyst
4. None of the above
The figure given below shows the conversions of a substrate into product by an enzyme. In which one of the four options (1-4), the components of the reaction labelled as A, B, C and D are identified correctly:
Options
A | B | C | D | |
1. | Transition state |
Potential energy |
Activation energy without enzyme |
Activation energy with enzyme |
2. | Potential energy |
Transition state |
Activation energy with enzyme |
Activation energy without enzyme |
3. | Activation energy with enzyme |
Transition state |
Activation energy without enzyme |
Potential energy |
4. | Potential energy |
Transition state |
Activation energy without enzyme |
Activation energy with enzyme |