?

Biochemistry

Free Version

Upgrade subject to access all content

Easy

Regulation in Blood Clotting

BIOCHM-VTRKW1

There are several enzymes that act in the blood clotting pathway, and it is critically important that these enzymes are only active at the appropriate time when blood needs to clot. Within the blood clotting pathway, factor X is activated by factor IX. If the primary structure of factor IX was compared before and after activation, the activated version of factor X is shorter.

Which choice below contains the type of regulation observed for factor X?

A

Factor X is an allosteric enzyme, and a positive effector was present.

B

Factor X is controlled by reversible covalent modification.

C

Factor X is an allosteric enzyme, and a negative effector was removed.

D

Factor X is synthesized as a zymogen and controlled by irreversible covalent modification.