Question

Comment on the specificity of enzyme action. What is the most important reason for their specificity?

Answer 1

Specificity of enzymes means the enzyme will catalyze only one or some particular or specific reactions and not others.

Complete step by step answer:
Enzymes vastly show specificity. This is essential because in this way enzymes will follow a particular pathway and it will act on specific substrates.
There are four types of enzyme specificity. There are –
-Absolute
-Group
-Linkage
-Stereochemical
Some enzymes are specific but not all.
Absolute specificity means the enzyme will act on only one reaction and catalyze that reaction only.
Group specificity means the enzyme will act on the molecules which have a particular functional group or some specific functional groups.
Linkage specificity means the enzyme will act on a particular type of chemical bond, the remaining part of the molecule does not matter.
Stereochemical specificity means the enzyme will act on a particular optical or stereochemical isomer and not on others.
Enzymes bind to the substrate in the following way:
$E + S \to \left[ {ES} \right]$
$\left[ {ES} \right]{{ }} \to EP$
$EP \to E + P$
At first, enzymes that are denoted by ‘E’ bind with substrates that are denoted by ‘S’. This is known as enzyme –substrate complex. This enzyme-substrate complex converts into a product and the enzyme separates away.

Note:
There are some regions on the surface of enzymes known as active sites. This is of a particular shape and specific substrates fit into this shape and bind with it. This is compared with lock and key. This lock and key model is the reason for specificity. For example, urease catalyzes hydrolysis of urea and not any other enzyme catalyzes this. Enzymes show specificity for their better efficiency.