Tag: surface chemistry

Questions Related to surface chemistry

Select the correct statements about enzymes.
chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. Enzymes arc biological catalysts found in organisms

  2. All enzymes are proteins

  3. Enzymes can catalyse any reaction

  4. Enzymes activity is optimum at $37^o C $

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Correct Option: A,D

Which of the following statements regarding enzyme inhibition is correct -

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  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 amount of substrate

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Correct Option: C
Explanation:
Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme because competitive inhibitor has a similar structure as that of a substrate, so it blocks the active site of an enzyme thereby reducing the production formation.

Enzymes, which catalyze biochemical reactions are very complex. They help in the reaction of very specific substances. This suggests that the enzyme and the reacting biochemicals are complementary to one another like a:

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. dog in his kennel

  2. horse and a rider

  3. lock and key

  4. leaf and a bud

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Correct Option: C
Explanation:

Enzymes are very specific in nature. Only those substrates that can fit into the active site of an enzyme can be bound within it. This specific action is similar to a lock and key where a key(reacting biochemicals) can only be used to actuate a specific lock(enzyme) and not all of them. 

Which of the following factors are responsible for the increase in the rate of a surface catalysed reaction?
I. A catalyst provides proper orientation for the reactant molecules to react
II. Heat of adsorption of reactants on a catalyst helps reactant molecules to.overcome activation energy
III. The catalyst increases the activation energy of the reaction 
IV. Adsorption increases the local concentration of reactant molecules on the surface of the catalyst
Select the correct answer using the codes given below:

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. I and II

  2. I and III

  3. I, II and IV

  4. I, II and III

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Correct Option: A
Explanation:

A catalyst works by providing an alternative reaction pathway to the reaction product. The rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.