Flashcards
Nutrient Absorption
Flashcards do conjunto (16)
- 1List the sources of carbohydratesSimple
- Monosaccharides
-Disaccharides
Complex
- Starch (plants)
- Glycogen (animals) - 2What needs to happen to starch, gylcogen, and disaccharides to be absorbed?They need to be broken down into monosaccharides
- 3Outline the process of carbohydrate digestionMouth - Salivary Amylase (starch > maltose)
Stomach - Salivary amylase inactivated (acidic environment)
Small intestine - Brush border enzymes (lactose, sucrase, maltose)
Pancreas - Pancreatic amylase (starch > maltose) - 4How is fructose different from other monosaccharides?It is a 5 ring molecule (as opposed to 6 ring)
- 5Amylase breaks down starch into two constituents. What are they? What other digestion occurs for the consituentsStarch > [amylase] > maltose + maltotriose
Maltose > [maltase] > 2 glucose - 6For carbohydrate absorption, what transporters are located on the luminal side1. Fructose uniporter
2. Glucose (or galactose)/ Na+ symporter - 7For carbohydrate absorption, what transporters are located on the basolateral side1. Glucose/galactose/fructose uniporter
2. Na+/K+ pump - 8Describe the process of protein digestionMouth - NO digestion in the mouth
Stomach - Pepsin (from pesinogen; polypeptides > small peptides)
Small intestine - Brush border enzymes (aminopeptidase + dipeptidase)
Pancreas- Trypsin, chymotrypsin, and carboxypeptidase - 9How do amino- and carboxypeptidases differ from pep-, tryp-, and chymotrypsin?Peptidases cut the very last A.A.s off.
- Creating individual peptides
Amino- : N-terminus
Carboxy-: C-terminus
-Sins cut polypeptides into smaller polypeptides - 10For fat absorption, what transporters are located on the luminal membrane?1. Di+tri-peptide/H+ symporter
2. H+/Na+ antiporter
3. Amino acid/Na+ symporter - 11For fat absorption, what transporters are located on the basolateral membrane? What occurs in the cell cytoplasm1. Amino acid uniporter
2. Na+/K+ pump
In the cytoplasm di+tri-peptides are broken down to amino acids by peptidase - 12Describe the fat absorption processMouth - Lingual Lipase (not activated)
Stomach - Lingual Lipase (activated)
Gastric Lipase
Small intestine - Pancreas - pancreatic lipase + colipase; Liver - bile (keeps lipids in solution) - 13Describe how bile salts help in fat absorptionEmulsification involves the bile salts surrounding the fat molecule with the sterol part of the salt inside the fat, while the carboxyl and polar parts affect the outside. The reaction causes a droplet of fat to become soluble in water
- 14How do Fatty acids get to lymphatic vessels1. Diffuse through luminal membrane
2. Repackaged into chylomicrons
3. Exocytosis to lymphatic vessels
4. Blood - 15Which vitamins are water-soluble?1. Vitamin C
2. B vitamins (except B12)
*Can overdose on fat soluble vitamins - 16Outline the process of fat vs. water-soluble vitamin absorption- Fat Soluble vitamins are found in lipid droplets in GI tract
- Bile and colipases induce micelle formation (helps absorption)
- Water-soluble vitamins require transport for absorption
- Vitamin B12 requires intrinsic factor (from parietal cells in the stomach)
Informações
- Descrição
- Universität Physiology (Digestive Physiology) FlashCards sobre Nutrient Absorption, criado por Amrit Bhogal em 01-03-2016.
- Criado por
- Amrit Bhogal
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