Digestion and Carb Digestion Flashcards
What is hydrolosis, chemically speaking?
A chemical reaction that breaks a covalent bond in a molecule by adding on an -OH group to one side and an -H bond to the other side, thus consuming an H2O molecule.
Digestion of food molecules occurs by ________
hydrolysis
Polymers are broken down into _________.
monomers
Disaccharide + H2O → ___________
monosaccharides
Peptide + H2O → _______ _______
Amino acids
__________+ __H2O → fatty acids + monoglyceride
Triglycerides
3
__% of dietary starch is digested before it reaches the small intestine.
50%
Generally, what to polysaccharides turn into? What are they called it the intermediate steps?
Monosaccharides
Oligo/tri/di - saccharides
What is an oligosaccharide?
A chain of 3-8 glucose molecules
In what percentages are the monosaccharides absorbed?
glucose (80%), galactose (20%), and trace fructose
What are the disaccharides?
Sucrose, lactose, maltose
What is SGLT?
Sodium glucose transporters (glucose is transported with Na+)
What is solvent drag?
As it travels through the epithelium, water carries with it a variety of dissolved solutes
Where does carbohydrate digestion and absorbtion occure?
Begins: Oral Cavity
Ends: Duodenum
What happens to salivary amylase in the stomach? Why?
It’s denatured by the low pH
WHat digests denatured salivary amylase?
Pepsin
When you swallow a bolus of food, it’s not a sphere, but little clumps, and the salivary amylase works inside the bolus until stomach acid penetrates it. T/F
True
Pepsin degrades proteins into _____
Amino acids
What does an endopeptidase do?
Cleave proteins into smaller peptides
What are the two endopeptidases?
trypsin and chymotrypsin
What does an exopeptidase do?
split one AA off from ends
What are the exopeptidases?
carboxypeptidase and aminopeptidase
What can only split dipeptide in the middle to release the 2 AAs from each other?
Dipeptidase
Protein digestion starts in the stomach with ______.
Pepsin
______ releases short-chain polypeptides and some AAs
Pepsin
Where is pepsin denatured?
In the small intestine
What are the 3 sources of AAs?
1- Dietary
2- Digestive enzymes
3- Rubbed off digested epithelial cells → digested into AAs
Where does most protein digestion take place?
Stomach and duodenum
Enterocytes have several __ dependent AA co-transporters to bring in AAs
Na+
How do AAs enter the enterocyte?
By fascilitated diffusion
How do babies get IgA?
Infants can absorb whole proteins by pinocytosis by enterocytes
