Exam Review - Chapter 18

Chymotrypsinogen procarboxypeptidases a and b

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: pepsinogen, the inactive form of pepsin o Pepsin is created by autocatalytic cleavage that occurs at a low pH o Low pH triggers secretion of secretin, which stimulates the pancreas to secrete bicarbonate and neutralize the acidity of the HCl o Cholecystokinin: stimulates the secretion of several pancreatic enzymes such as trypsinogen, chymotrypsinogen, procarboxypeptidases A and B Trypsinogen is converted to its active form by enteropeptidase • Activates chymotrypsinogen, procarboxypeptidases, and proelastase o Carboxypeptidases remove carboxyl- terminal residues from peptides o Aminopeptidases: remove amino- terminal residues from short peptides Removal of the α- amino groups is the first step of amino acid catabolism o Promoted by enzymes aminotransferases or transaminases o Amino group is removed from amino acid and transferred to α- ketoglutarate All aminotransferases have same prosthetic group and same reaction mechanism o Pyridoxal phosphate: the prosthetic group Functions as an intermediate carrier of amino groups • Can accept and donate amino groups Participates in a variety of reactions at the α, β, and γ carbons of amin acids • Reactions at the α- carbon include racemizations, decarboxylations, and transaminations Pr...
View Full Document

This note was uploaded on 02/06/2014 for the course BCHB 501 taught by Professor Jessicajones,elliottcrooke,ericgalsgow,marybethmartin during the Fall '12 term at Georgetown.

Ask a homework question - tutors are online