07 Carbs Digestion Flashcards
When asked about digestion you think …….
Enzymes
When asked about absorption you think ……
Transporters
1st grout of wnzymes to work in carbs is……..
Amylase
2nd group of enzymes ro work in carbs difestion is ……
Disaccharides
Carbs are the major source of …….
They provde About ……… of calories in the diet
Glucose
40-60 %
1g of carbs = …….. calories
4
What are th 3 groups of carbs
Simple carbs ( monosaccharides) Disaccharides Complex carbs
Purpose / goal of carbs digestion?
Break down complex carbs and disaccharides into monosaccharides to be absorped
Are all carbs absorped?
No . E.x fiber is not absorped
Amylase contains 2 types of enzymes …….. and …….
Slivary and pancriatic
Slivary amylase is the first to work in ……… and it is produced in ……
Mouth
Mouth in serous cells of slivary glands
Pancriatic amylase is produced/made in ………. And released in ……. To work there
Pancrias acinar cells
Small intastine
Slivary Amylaze breaks down starch into …..
Maltose and oligosaccharides
What is the enzyme that is sensitive to PH ?
Amylase
That is why it is inhibited in the acidic invironment of the stomach
Where does carbs digestion happen
Mouth and small intastine
Not in stomach
Why there is no carbs digestion in stomach
Acidic inviroment inhibits amylase since amylase is sensetive to PH
What stimulates the release of pancriatic amylase?
Secretin and CCK
What bonds does pancriatic amylase target?
Alpha 1,4
It is unable to break alpha 1,6 or terminal bonds
Oligosaccharides and disavcharides are digested by ……… enzyme in the …….
Disaccharidase Microvillus membrane ( brush border)
Brush border enzymes are synthesized in ……….. and glycosylated in ……… of rhe entrocyte. Then trafficked to the apical membrane.
Endoplasmic reticulum
Golgi apparatus
Why is disaccharisase enzyme glycosylated?
To protect it from proteolysis( digestion)
When does full term of disaccharidase enzyme happens?
In delivary
So during gestation these enzymes vary
Sucrase and lactase are …….. enzymes
Disaccharidase
Sucrase appears in ………..: while lactase reaches normal levels at
About 20 weeks of pregnancy
3rd trimester/month
Carbs which are not digested in small intastine goes to ……….. where …….. digest them
Large intastine
Colonic bacteria
When colonic bacteria digest carbs, ……….. are released
Short chain FA (SCFA) like propionate, butyrate, acetate
These SCFA provide nutrition to colonocytes/bacteria which causes diarrhea and abdominal cramping
Diarrhea happens due osmosis
How is lactase enzyme and lactose intolerance related to SCFA and colonocytes?
When lactase( a disacchridase) is deficient lactose can not be digasted. This causes increased osmotic load in small intastine and SCFA high production in colon
When this enzyme goes to small intastine. Bacteria digest it and it causees pain and diarrhea
After digestion comes absorption then transportation to …..
Portal circulation
Digestion and absorption are coupled, with the enzymess closley located in the …..
Appropriate transporters
Glucose and galactose are absorbed in small intastine lumen through …………… then apsorbed again to get to circulation through
SGLT-1 transporter
GLUT-2 transporter
GLUT-2 and GLUT 5 both uses ……
Facilitated diffusion
SGLT-1 uses…….
Active secondry transport that needs ATP
From intestinal lumen to inside small intestine cell, transporters of brush border do the absorption.
What are these transporters?
SGLT-1 ( absorpes glucose and galactose) and GLUT-5 ( absorpes fructose)
From inside the small intastine cell yo the blood, other transporters continue the absorption. What are these?
GLUT-2 ( absorpes galactose, glucose and frucrose)
If any problem happens in the transporters, the molecules will mot be absorbed. True or false?
True
Fructose is absorped via …………….. by transporters ………..
Facilitated diffusion
GLUT5 and GLUT2
Facilitated diffision utilizes a carrier protien to achieve greater transport rate than simple diffusion. True or false?
True
Ther is a debate about passive glucose absorption. Does it exist?
Yes
Which disacchridases increase by carbs intake ? and which are not affected by the diet ?
Sucrase and maltase increase when carbs are high
Lactase production is not affected by diet
What causes pancreatic insufficiency?
Cystic fibrosis, chornic pancreatitis, pancreatic duct obstruction(tumor).
Due to decreased release of enzymes so inadequate/insufficient carbs digestion, which leads to malabsorption.
Celiac desease( an autoimmune disease) is related to ….
Gluten intropathy
What is celiac disease ?
Decreased villus length which means decreased absorptive capacity. Meaning disacchridase enzymes are less.
To heal, gluten free diet produces mucosal healing then disaccharidase deficiency goes away/abates.
