Question

Non-competitive inhibition often results in
A) Change in enzyme structure
B) Blocking of active site
C) Non-synthesis of enzymes
D) Non-availability of cofactor

Answer 1

Hint:Inhibition, in enzymology, a phenomenon in which a compound, called an inhibitor.Instead of interfering with the amount of substrate binding to the enzyme, this form of inhibition reduces an enzyme's turnover rate.

Complete answer:
i) A molecule that disrupts the usual reaction pathway between an enzyme and a substrate is an enzyme inhibitor.
ii) Depending on their mechanism of action, enzyme inhibitors may be either competitive or non-competitive.
iii) Enzyme inhibitors prevent the formation of a complex of enzyme substrates and thus prevent the formation of a substance.
iv) Depending on the precise impact of the inhibitor used, enzyme inhibition may be either reversible or permanent.

Noncompetitive Inhibition
-A molecule bound to a site other than the active site requires non-competitive inhibition (an allosteric site).
-A conformational change to the active site of the enzyme allows the binding of the inhibitor to the allosteric site.
-The active site and substrate no longer share specificity as a result of this shift, meaning the substrate can not bind.
-As the inhibitor is not in direct competition with the substrate, rising levels of the substrate do not mitigate the effect of the inhibitor.
-Cyanide (Noncompetitive Inhibitor Example).
-Cyanide is a toxin that inhibits the production of ATP by aerobic breathing, leading to eventual death.
-This binds to the cytochrome oxidase allosteric site, a carrier molecule that forms part of the electron transport chain.
-Cytochrome oxidase can no longer transfer electrons to the final acceptor by adjusting the form of the active site (oxygen).
-As a result, the electron transport chain does not continue to work and ATP is not produced by aerobic respiration.
Thus the correct answer is option (A) i.e, Change in enzyme structure.

Note:Its function in the control of metabolism by feedback inhibition is one example of the importance of non-competitive inhibition. In feedback inhibition, the metabolic pathway products serve as enzyme inhibitors in that particular pathway.