Controlling activity in the cell

Question 1

What are the categories of larger scale proteolysis?

Answer 1

Digestive enzymes
Blood clotting
Complement activation

Question 2

What are the types of cellular proteolysis?

Answer 2

Downregulation
Desensitisation
Activation
Cell death

Question 3

What are the major cellular locations of proteolysis?

Answer 3

Proteasome

Lysosome

Question 4

What is ubiquitin?

Answer 4

76 amino acid polypeptide
Conjugated via Gly-76 to lysine or to another ubiquitin molecule
Poly ubiquitylated proteins are recognised by the 26S proteasome and degraded

Question 5

What is the role of ubiquitin K11 and K48?

Answer 5

Targets proteins for proteasome-mediated degradation

Question 6

What is the anaphase promoting complex?

Answer 6

Regulates progression through mitosis and G1 phase

Question 7

What activates the anaphase promoting complex?

Answer 7

CDC20

CDH1

Question 8

What is the structure of a 26S proteasome?

Answer 8

Made up of a 20S proteoasome and a 19S complex

Question 9

Describe the 20s proteasome

Answer 9

Barrel shaped symmetrical structure
2 copies of each of 14 distinct subunits
7 alpha and 7 beta
Proteolysis occurs in the central channel

Question 10

What enzymes are associated with the 20s proteasome?

Answer 10

B1 caspase
B2 trypsin
B5 chymotrypsin

Question 11

Describe lysosomes

Answer 11

0.2-2nm in diameter
Membrane bound organelles
40 lysosomal hydrolases
Formed in the golgi apparatus