GENERAL HISTOLOGY

Detailed explanation-1: -Active site of an enzyme is the location on the enzyme where the substrate binds to initiate a chemical reaction.

Detailed explanation-2: -Enzymes bind substrates at key locations in their structure called active sites. They are typically highly specific and only bind certain substrates for certain reactions.

Detailed explanation-3: -The buttressing group is the part of the active site of enzymes that supports substrate by providing the substrate binding site. The active sites have only two parts; catalytic group and buttressing group.

Detailed explanation-4: -An enzyme, for example ATCase, contains two distinct subunits: an active site and a regulatory site. The active site is the catalytic subunit, whereas the regulatory site has no catalytic activity.