Intro to BCH and Endo Valencik Flashcards
Fat gets broken down into what three things?
FFA, MAG and DAG
What does MAG get further broken down into?
glycerol
(blank) are digested to yield di and monosaccharides
polysaccharides
(blank) yield the component AA and di or tripeptides
proteins
Fat is ingested mostly as (blank) (triglycerides, TAG), the esters of glycerol and fatty acids.
triacylglycerols
During digestion a stepwise removal of fatty acid molecules takes place yielding (blank) and (blank)
free fatty acids
2-monoacylglycerols.
What are the three main phases of digestion?
mechanical phase
hydrolysis
tranposrt
The mechanical phase begins in the mouth with (blank( and continues into the stomach with (blank)
mastication, peristalsis
Hydrolysis begins in the (blank), continues in the (blank) and the major players in hydrolysis are in the (blank)
mouth
stomach
small intestine
After the completion of hydrolysis, at the surface of the (blank), we have transport of small molecules across the (blank) where they can enter the blood stream
small intestine
intestinal wall
What does the mechanical phase consist of?
mastication and peristalsis
What is the goal of the mechanical phase?
to homogenize nutrients
What are the 3 functions of gastric acid?
1: kill microbes
2: denature proteins
3: makes the pH optimum for activation and enzymatic activity of pepsin
What enzymes aid with hydrolysis in the mouth?
α-amylase (pH 6.5-7)
Lingual lipase
Lysozyme (β 1,4 bonds
What kind of bonds do lysozymes hydrolyze?
beta 1,4 bonds
What pH is α-amylase optimal at?
pH of 6.5-7
What enzymes aid with hydrolysis in the stomach?
HCl pH 2.0
pepsin
What is the optimal pH of HCl?
2.0
What enzymes aid with hydrolysis in the small intestine?
α-amylase (isoenzyme) Glycosidases Proteases Lipases Bacteria `
The (blank) is where protein digestion is initiatied.
stomac
(blank) kills microorganisms, denatures protein, creates the pH necessary (<5.0) to first cleave pepsinogen and than the pH necessary for pepsin activity (≈ 2.0).
HCl
What allows for the cleavage of pepsinogen and the activity of pepsin?
optimal pH created by HCl
When acid hits the duodenum, the (blank) secretes bicarbonate to neutralize the chyme
pancrease
Hydrolysis begins at the mouth where (blank) starts to digest carbohydrates.
alpha amylase
(blank) binds to the surface of fat globules in the mouth and begins liberating free fatty acids.
lingual lipase
the (blank) secrete lysozome
salivary glands
(blank) primarily digests beta 1,4 glycosidic bonds found in the peptidoglycans that make up the bacterial cell walls. This helps to kill off the bacteria that you just happen to ingest.
lysozyme
In the stomach (blank) begins to denature proteins and drops the pH of the food creating an environment where pepsinogen is cleaved to pepsin.
HCl
Pepsin is an (blank) that cleaves proteins.
endopeptidase
Once chyme is released into the duodenum, (blank) are released and activated to continue the hydrolysis.
pancreatic zymogens
α-amylase (isoenzyme), Glycosidases, Proteases and Lipases (blank) the hydrolysis carbohydrates, proteins and fats
complete
There is also hydrolysis by (blank) that reside in the intestinal tract.
bacteria
What is an an isoenzyme of salivary alpha amylase?
pancreatic alpha amylase
The enzymes in the salivary glands are mostly there for (blank)
cleaning teeth
Once you have all the food digested to the appropriate metabolites, the metabolites will be absorbed into the (blank)
intestinal epithelial cells
What metabolites can be absorbed/transported from carbs? proteins? fat?
monosaccharides
AAs, di- or tri- peptides
free fatty acids, 2 monoacylglycerides, glycerol
What four hormones are secreted as endocrine hormones in the GI tract?
cholecystokinin
gastrin
histamine
secretin
The chyme (carbs, protein, lipids and acid) from the stomach enters the duodenum and stimulates the ENDOCRINE secretion of (blank) and (blank)
cholecystokinin (CCK) and secretin.
Food entering the stomach stimulates an increase in (blank) secretion which stimulates histamine which stimulates HCL. HCl will then decrease pH which will increase (blank) and decrease gastrin.
gastrin
somastatin
(blank) (neurotransmitter) is the major neurotransmitter that stimulates electrolyte secretion in the intestinal mucosa.
acetylcholine
(blank) is a peptide that regulates fluid secretion at the brush border (acts on guanylyl cyclases)
guanylin
Decreasing pH down-regulates gastrin secretion via (blank).
somatostatin
(blank) stimulates the watery/bicarbonate (HCO3-) phase of pancreatic excretions.
Secretin
(blank) stimulates the secretion of zymogens from the pancreas, increases bile production in the liver and stimulates contraction of the gallbladder (bile secretion).
CCK (pancreozymin)
How does the pancreas protect itself from the digestive enzymes it produces?
proenzymes (aka zymogens)
is enzyme secretion and endocrine or exocrine process?
exocrine