A variety of factors influence enzyme activity. Substances that bind to the enzy

Question

A variety of factors influence enzyme activity. Substances that bind to the enzyme and interfere with substrate binding or catalysis are inhibitors. Identify the type of inhibition associated with each of the following descriptions and examples by sorting each item into the appropriate bin. Irreversible inhibitiorn Competitive inhibition Mixed inhibition malonate, which resembles succinate, binds to the succinate dehydrogenase active site inhibitor may permanently modify an enzyme the Alt ion binds to acetylcholinesterase or to the Not ans inhibitor increases Km but not Vnx DIPF permanently modifies the hydroxyl group of a Ser residue at the active site inco sing appe indic one the p complex binding by the inhibitor increases K, but decreases Vees

Explanation / Answer

Q) Identify the type of inhibition associated with each of the following descriptions and examples by sorting each item into the appropriate bin.

Answer:-

Explanation:- A variety of factors influence the enzyme activity . substances which bind to the enzyme and interfere with substrate binding or catalysis are inhibitors, These three are the major inhibitors they are i) Irreversible ii) Competitive iii) Mixed inhibitor.

i) Irreversible inibitors:- These are the inhibitors which bind to the enzyme so that no other Enzyme-substrate complex can be formed.It binds to the enzyme by a covalent bond at the active site and makes the enzyme denatured.

ii) Competitive inhibitor:-  This is a type of enzyme inhibition, in which inhibitor resembles with the normal substrate and binds to the enzyme, at the active site, preventing the substrate to bind . During competitive inhibition, the inhibitor and substrate compete for the active site.

Vmax is the maximum velocity of the reaction, and Km is the amount of substrate required to reach half of the Vmax

Here Km increases but Vmax remains same because  once substrate binds, the reaction proceeds normally, so Vmax depends on the maximum possible ES complex concentration and the maximum ES concentration depends only on the total amount of enzyme present.

example of competitive inhibition is malonic acid it competes with succinate for active site of succinic dehydrogenase.

Mixed inhibition:- It is the type of inhibition in which inhibitor may bind to the enzyme whether the enzyme is already bound to the substrate or not..

It is called "mixed" inhibition because, it is seen as a "mixture" of competitive inhibition, (in which the inhibitor only binds to the enzyme if the substrate is not already bound), and uncompetitive inhibition,( in which the inhibitor can only bind the enzyme if the substrate is already bound).

In mIxed inhibitor Km increases and Vmax decreases. Vmax decreases because here the inhibitor is capable of preventing catalysis whether the substrate is bound to the enzyme or not.

Example of Mixed inhibitor is Al3+ Binds to Acetyl-colinesterase or Acetyl -colin esterase- substrate complex .

Irreversible inhibition Competitive inhibition Mixed inhibition Inhibitor may permanently modify an enzyme. Binding by Inhibitor increases Km but not Vmax Binding by the Inhibitor increases Km but decreases Vmax. DIPF, permanently modifies the hydroxyl group of a Ser residue at the active site malonate which resembles succinate, binds to the suucinate dehydrogenase active site The Al3+ ion binds to acetylecolinesterase or to the acetylcolinesterase- substrate complex.

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