Final answer:
The separation of aspartate transcarbamoylase (ATCase) into regulatory and catalytic subunits, and their reconstitution, has important biological significance in enzyme regulation and pyrimidine production.
Step-by-step explanation:
The observation that aspartate transcarbamoylase (ATCase) can be separated into regulatory subunits and catalytic subunits, and when isolated regulatory and catalytic subunits are mixed, the native enzyme is reconstituted, has important biological significance in terms of enzyme regulation and function.
The regulatory subunits of ATCase act as allosteric molecules that bind to the catalytic subunits and modulate their activity.
By undergoing conformational changes, the regulatory subunits can activate or inhibit the catalytic subunits, allowing for fine-tuned regulation of the enzyme.
This separation and reconstitution process allows cells to control the activity of ATCase and regulate the production of pyrimidines, which are essential components of DNA, RNA, and other important cellular molecules.