with Correct and Verified Answers 100% Rated
A+ Graded-GCU
What happens during carbohydrate digestion in the mouth?
Salivary a amylase hydrolyzes a(1,4) glycosidic linkages of amylopectin and amylose
What happens during carbohydrate digestion in the stomach?
Nothing. Salivary amylase continues in the stomach until gastric acid inactivates it due
to the low pH.
What happens during carbohydrate digestion in the small intestines?
Digestion and amylose and amylopectin
-pancreatic a-amylase in duodenum/jejunum hydrolyzes a(1,4) glycosidic linkages
-oligosaccharides/maltose broken down by brush border, leaving dextrins
-a-dextrinase hydrolyzes the remaining a(1,6) glycosidic linkages of amylopectin
What happens in the mouth and stomach during fat digestion?
Mouth: Lingual lipase produced in salivary glands released by serous glands
,Stomach: Gastric lipase produced in the stomach
-Most are used in infants.
-Medium and short FA in sn-3 position
What happens in the small intestines during fat digestion?
Phase 1: Emulsification (bile)
Phase 2: Pancreatic lipase produced in pancreas for enzymatic digestion
Glycerol, MAG, long chain FA are absorbed into the enterocyte
Partially hydrolyzed lipid emulsion leaves stomach and enters duodenum as small lipid
droplets.
Bile salts mix from stimulated CCK and secretin
Micelle = soluble form to be absorbed into enterocyte
What is the protein digestion process?
1. Gastric juices released, HCl denatures proteins and converts pepsinogen into pepsin
(hydrolyzing peptide bonds)
2. Partially digested proteins enter the small intestines, CCK and secretin are released
which stimulate the pancreas to release pro-enzyme and bicarbonate in intestines
,3. Pancreatic pro enzyme are activated that digest polypeptides into tri, dipeptides, and
free amino acisd
4.Intestinal enzymes in lumen of small intestines and within mucosal cells complete
the digestion
Pepsinogen
-Activator, Enzyme, Site
HCl, pepsin, stomach
Trypsinogen
-Activator, Enzyme, Site
Enteropeptidase, trypsin, intestines
What are the two methods of transportation for absorption of glucose and galactose?
Facilitated, Active
-depends on amount of carbohydrates
-facilitated occurs after a significant carbohydrate intake
What is the location of SGLT1?
, intestinal lumen side of enterocyte in brush border
Active Transport of Glucose Process
Requires ATP and SGLT1
1. SGLT1 transports 1 molecule of glucose and 2 molecules of Na+ in the same direction
- SGLT1 has two active binding sites (glucose and Na+) Glucose doesn't open for
binding until Na+ has bounded
-Na+ increases transport protein's affinity for glucose
2.Glucose is released once transported
3. Na+ that entered the cell is pumped back out by the energy-requiring Na/K+ ATPase
located in basolateral membrane
What is the mechanism of the Na/K+ ATPase?
Combines ATP in presence of Na+ on inner surface, enzyme phosphorylated by ATP to
ADP and moves 3 Na+ out of the cell
Outer - ATPase becomes dephosphorylated by hydrolysis in presence of K+ and
returns 2 K+
Facilitated Transport of Glucose Process
(without SGLT1)