quiz Flashcards
Digestion of proteins begins in the _____
- stomach
what are necessary for protein hydrolysis
- pepsin
- hcl
HYDROCHLORIC ACID - acid secreted by the ______
- parietal cells
used to kill some bacteria, denature proteins, making them more susceptible to subsequent hyrolysis by the _____
proteases
used to kill some bacteria and to
denature proteins, making them more susceptible to subsequent hydrolysis by proteases
parietal cells
an acid-stable endopeptidase secreted by the ______
- serous cells
as an inactive zymogen called _____
- pepsinogen
that is activated by HCI or autocatalytically by other pepsin molecules.
- pepsinogen
Pepsin breaks down and releases ______ and a few free amino acids from dietary proteins.
peptides
On entering the small intestines, large polypeptides produced in the stomach by the action of ______ are further cleaved into _____ and amino acids
- pepsin
- oligopeptide
TRYPSIN - secreted as _____ then activated by _________
- trypsinogen
- enteropeptidase
enteropeptidase an enzyme synthesized by the _________ otherwise known as enterokinase. It hydrolyzes the polypeptide chain from the carboxyl end of ______ and _______
- intestinal mucosal cells
- arginine and lysine
plays as the common activator of all pancreatic zymogens.
- trypsin
CHYMOTRYPSIN - secreted as _____ and activated by _____ molecules.
- chymotrypsinogen
- trypsin
In chymotrypsin, It hydrolyzes the polypeptide chain from the carboxyl end of (5)
- tyrosine
- tryptophan
- phenylalanine
- met
- leucine
____ secreted as proelastase and is activated by trypsin molecules. It hydrolyzes the polypeptide chain from the carboxyl end of ______, ____, _____
- ELASTASe
- alanine
- serine
- glycine
CARBOXYPEPTIDASE A - secreted as ______ and is activated by trypsin molecules. hydrolyzes the poly peptide chain from the carboxyl end of (4)
- procarboxypeptidase A
- ala
- isoleucine
- leucine
- valine
CARBOXYPEPTIDASE B - hydrolyzes the polypeptide chain from the carboxyl end of arginine and lysine, similar to _____
myosin
______ - The luminal surface of the small intestines contains ________
- internal digestion
- aminopeptidase
an exopeptidase that repeatedly cleaves the N-terminal residue from oligopeptides to produce free amino acids and smaller peptides.
- aminopeptidase
These amino acids are absorbed mainly in ______ through the portal circulation and slightly through the _____
- small intestine
- lymphatics
amino acids enter the cells by _____
- active transport
maximum concentration in blood is attained range minutes after eating
- 30 to 50 mins
amino acid nitrogen level is kept more or less constant between __ to ___ of blood plasma.
- 4-8 mg per 100 ml
other name of nitrogen balance
equilibrium
occurs when protein intake is equal or about the same as the protein breakdown.
- nitrogen balance
This condition is typified by young adults whose protein intake is just enough to replace the daily amount of protein used.
nitrogen balance
implies a net gain of protein in the body.
- positive nitrogen balance
positive nitrogen balance - This is found whenever new tissues are being synthesized as in (3)
- growth stage
- convalescence
- pregnancy
protein intake exceeds protein output
- positive nitrogen balance
Implies greater protein utilization than protein intake, causing loss of protein from body
- negative nitrogen balance
negative nitrogen balance examples: (4)
- kwashiorkor disease
- marasmus
- lactation
- albuminuria
Inadequate intake of proteins as in fasting, diarrhea and malnutrition disorders
- kwashiorkor disease