Chapter 14: Digestion and some Chapter 15: Metabolism Flashcards
Digestion will have no __________.
ATP Production
Mechanical and chemical breakdown; prep stage
- proteins
- -AAs
- polysaccharides
- sugars
- fat
- fatty acids
Digestion
From AAs, sugars, fatty acids
-small amount of ATP production
Acetyl CoA Production
Citric acid cycle and oxidative phosphorylation
ATP Production (90% of energy generated)
Stomach
- pH 1-2, denaturation of proteins
- Pepsin (protease) breaks peptide bonds
- Protein fragments move to small intestine
Pepsin shows optimal activity in the _____, only one of few that can be active in these conditions.
Stomach
Small Intestine
- low pH of food stimulates the release of secretin
- secretin stimulates release of sodium bicarbonate from pancreas to neutralize pH of the food
- Oligopeptides stimulate CCK -CCK causes secretion of digestive enzymes from pancreas and bile salts from gallbladder
Zymogens are…
Proenzymes secreted from pancreas as inactive precursors
Enteropeptidase activates…
Trypsinogen to Trypsin
Enteropeptidase is the only enzyme in the ________.
Small Intestine
Trypsin activates…
Remaining pancreatic zymogens
-only activated in SI and all at the same time
Zymogens start in the _______ form so that they cannot destroy the ______.
Inactive Pancreas
Pancreatic proteases hydrolyze proteins to _______ and small _______ in the intestines.
Animo acids and small oligopeptides (protein fragments)
Oligopeptides are cleaved into AAs and di- and tri- peptides by…
Intestinal peptidases
AAs are released into….
The blood for use by other tissues
Primary source of dietary carbohydrates are…..
Complex carbs (ie. starch - small amounts of glycogen)
Starch is digested by….
a-amylase
a-amylase cleaves
1,4-bonds NOT 1,6
Products of starch…
Maltose, maltotriose and limit dextrin (has a-1,6 bonds)
Maltose converted to glucose by… Maltotriose is digested by… Limit dextrin is digested by
Maltase a-glucosidase a-dextrinase to simple sugars
Disaccharides are…
Sucrose and Lactose