2.8 & 2.9 Protein Digestion Flashcards
Name the Non-Essential Ketogenic AA
NONE
Name the ketogenic Essential AA
Leucine and Lysine
Name the Glucogenic Essential AA
Histidine, THreonine, Methionine and Valine
Name the Glucogenic and Ketogenic Essential AA
Isoleucine
Tryptophan
Pheynlalanine
Name the Non essential Glucogenic and Ketogenic AA
Tyrosine
What is ketogenic?
An amino acid that is degraded to Acetyl-CoA or Oxaloacetate.
Cannot be converted to glucose
Role of HCl in protein digestion
Reduces pH to 1-2 which allows denaturation of dietary proteins
What activates Pepsin?
Low pH and other active autoactivate pepsin as well
Cholescystokinin is stimulated how in protein digestion and what are its function
It is stimulated by protein leaving the stomach
It stimulates release of pancreatic enzymes
It stimulates release of bile
It stimulates slow gastric empyting
Role of Secretin in Protein digestion
Activates release of bicarbonate solution from pancreas to neutralize the pH of intestine
What is the role of Enteropeptidase?
To convert trypsinogen to its active form trypsin
T or F, Pancreatic enzymes are released into small intestine as zymogens
True
What catalyzes Pepsinogen –> Pepsin
Low pH or other active pepsin
What is the role of pepsin
Degrade large peptide fragments and some free amino acids
What catalyzes Chymotrypsinogen –> CHymotrypsin
Tryspin
What substrates does chymotrypsin act on?
Aromatic Amino Acids
What does Trypsin digest?
Arginine and Lysine residues
Elastase has substrate specificity for what?
Hydrophobic Amino acids
What are the major end products of protein digestion?
Free Amino Acids
Dipeptides
Tripeptides
How are dipeptides and tripeptides transported across intestinal cell?
By using an H+ symporter
How are Free Amino Acids transported into intestinal cell?
Using a Na Symporter
How are all amino acids taken up by the capillary?
By using a Na Symporter
What is Ubiquitin?
It is a marker that tags proteins for degradation by the proteasome
T or F, Few Amino Acids are reincorporated into new proteins within the body
False, Most amino acids are.
What are the three determinants of Protein longevity
Oxidation
PEST Sequences
Amino Terminal Residues
What is the significance of Amino Terminal residues?
Some have high stabalizing residues while others have destabalizing. This determines the longevity of the AA
What are the 4 PEST Sequences
Glutamate
Proline
Serine
Threonine
