Lecture 28 Flashcards
How are amino acids consumed in the diet?
As proteins
What does protein digestion involve?
Hydrolysis of peptide bonds by different proteases / peptidases
What are the two types of peptidases?
Endopeptidase and exopeptidase
What do endopeptidases do?
Attack peptide bonds within the protein polymer
What do exopeptidase do?
Attack the last peptide bond near the end of the protein polymer
What are the types of endopeptidases?
Pepsin, trypsin, chymotrypsin
How do endopeptidases work?
Different endopeptidases act sequentially to produce smaller peptides each round
What is endopeptidase specificity determined by?
Adjacent amino acid side chain in the protein substrate
What are the types of exopeptidases?
Carboxypeptidases and aminopeptidases
Where do carboxypeptidases cut?
Near the carboxyl-terminal residue
Where do aminopeptidases cut?
Near the amino-terminal residue
What are proteases produced as?
Zymogens
What are zymogens?
Inactive precursors to the peptidase / protease
Why are zymogens needed?
To prevent peptidase activity before reaching the GIT and breaking down the proteins within cells
How are zymogens activated?
Through cleavage of peptides from their structure