Regulation of enzyme activity Flashcards
What are isoenzymes?
They are different forms of the same enzyme with different kinetic properties
Give a type of short term regulation of enzyme activity.
- Substrate and product accumulation
- Allosteric regulation
- Covalent modification
- Proteolytic cleavage
What is a zymogen?
An inactive enzyme
What is the advantage of using a zymogen?
it allows for inactive forms to be transported safely to their sites of action
What are the name of the two pathways associated with the blood clotting cascade?
Extrinsic and intrinsic
What domains keep prothrombin in its inactive form?
Kringle domains
What is Vitamin K’s role in the blood clotting cascade?
Cofactor for Gla residue formation in most of the tissue factors?
What are Gla residues?
They’re a special amino acid residue that is found on the tissue factors and prothrombin. They interact with Ca2+ and hence the sites of damage and platelets.
What is the name of the process that causes the dissolution of the fibrin clot?
Fibrinolysis
Both pathways in the intrinsic and extrinsic pathway produce which factor?
Factor X
What is the purpose of thrombin in the blood clotting cascade?
Thrombin cleaves fibrinopeptides from the central globular domain of fibrinogen
How is the fibrin clot stabilised?
The clot is stabilised through amide bond formation via transglutaminase activity
What are the five main mechanisms which regulate the blood clotting cascade?
- Inactive zymogens present at low concentration
- Amplification of an initial signal
- Amplification of clotting factors at site of damage
- Feedback activation by thrombin
- Termination of clotting by multiple processes
Allosteric regulation shows a sigmoidal type of relationship. True or false?
True
