Nutrients Digestion and Absorption: Carbohydrates and Proteins Flashcards
What and where are disaccharides broken down?
Broken down into monosaccharides (glucose) by brush border enzymes in the small intestine
What is the monosaccharides of:
Lactose
Sucrose
Maltose
Glucose and galactose
Glucose and fructose
Glucose and glucose
What are the two forms of starch and their bonding
Amylose and amylopectin
Both glucose monomer linked by alpha 1 glycosidic bonds
What polysaccharide cannot be broken down in vertebras
what is its structure
Cellulose
unbranched linear glucose molecules linked by beta 1-4 glycosidic bonds
What is the linkage in polysaccharide glycogen
Glucose monomers linked by alpha 1-4 glycosidic bonds
What enzymes breaks down the polysaccarides glycogen and starch
and where can it be found
amylase
Found in your saliva
Whats the name of the out facing membrane on the brush border of the small intestine
apical membrane
What is the name of the inside facing membrane of the brush border of the small intestine
Baso-Lateral facing membrane
What is found on a brush border, and what is its purpose
Micro Vili covered surface
Increasing the surface area
What is the three pathways across the small intestine
Transcellular - right travel through apical and basolateral membranes
Paracellualr - travel through tight junction of brush border cells
Vectorial - a proteins carriers that travel in one direction
What does glucose couple up with in secondary active transport across the brush border and why?
Na
There is a continually driving force for sodium to enter the cell
Why cant glucose cross the brush border cell on its own
Is water soluble and charged
what is name of transporter that glucose and sodium both bind to
SGLT1
What happens to glucose when it is pumped into the cell
Glucose stays in the cell until a concentration gradient of above 5.5 mmol/L is created and glucose is transported across the cell
What is the name of the glucose transporter that transports glucose out the cell and into the blood
GLUT 2
What happens to sodium once it enters the cell
Sodium enters the cells and is pumped out by active transport
How is fructose transported across the cell and into the blood from the small intestine
GLUT 5 transports fructose from lumen into the cell and fructose is pumped out the cell through GLUT2 into the blood
Why does fructose enter the small intestine without coupling to sodium
Their isn’t a fructose gradient present
What are the enzymes that hydrolyse peptide bonds in protein digestion
Protease and peptidase
What is the difference between endo and exopeptidase
Endopeptidase cuts peptide chain anywhere minus the terminal ends
Expedites cuts the peptide chain at the terminal ends
How does an amino acid cross the brush border of the small intestine
Uses the driving force of sodium and combines with sodium at the SAAT1 transporter
How does sodium and amino acid pass from the small intestine to the blood
Sodium is actively transported across the cell
Amino acid is transported across into the blood
What is the name of the transported for dipeptides and most proteins across the brush boarder
PepT1
What couples up with Dipeptide to cross the brush border
Hydrogen
What is the name of the NA/H transporter across the brush boarder
NHE3
Due to movement of hydrogen across the brush boarder what is created
An acid microclimate
