Metabolic regulation 3

Question 1

Proteolytic Activation

Answer 1

Enzymes has to be reduced by the cell (active form of protein)
E.g in the stomach, pepsinogen is converted into pepsin
In the pancreas Chymotrpsinogen is converted into chymotrypsin.

They act as proteases

Question 2

Trypsin and chymotrypsin

Answer 2

T and C
Trypsin cleaves proteins at the C terminus of lysine and argenine residues

Chymotrypsin cleaves C terminus at tyrosine, rypsophan and phenylalanine, leucine, and methionine

Question 3

Pancreas Acinar cells

Answer 3

Grow around central duct, they secret digestive enzymes.

Question 4

Trypsinogen and chymotrypsinogen synthesis

Answer 4

On the rough ER
Transported to the golgi, in secretory granules
They are made as inactive form to stop breakdown within the cell.

Question 5

Inactive > Active form

Answer 5

Trypsinogen
Proteolytic event, it is activated by enzyme, Enteropeptidase, cleaving a lysine residue.
Once the lysine residue is cut, it will self amplify the reaction.

Chymotrypsinogen
Trypsin is used to cleave first 15 amino acids
re-arrangement of the protein occurs

Question 6

Chymotrypsin structure

Answer 6

Catalytic triad, which undertakes catalysis itself.

Question 7

Proteolytic enzyme specific inhibitors

Answer 7

The proteolytic activation is irreversible

To turn off the system, the cell releases an inhibitor which binds to the active site.