Unit 3 Reading 16 Flashcards
Absorption
(in animals) the uptake of ions and small molecules (from food) across the living of the digestive tract
Antiporter
Carrier protein that allows an ion to diffuse down an electrochemical gradient (using energy to transport a different substance in the opposite direction)
Cotransporter
Transmembrane protein that facilitates diffusion (to transport some other substance in the same or opposite direction)
Digestion
Physical and chemical breakdown of food into molecules that can be absorbed into the body of an animal
Essential nutrients
Any chemical element, ion, or compound that is required for normal growth, reproduction, and maintenance of living organisms (cannot be synthesized by the organism)
Food
Any nutrient-containing material that can be consumed and digested by animals
Epithelial Cell
Tissue consisting of sheetlikke layers of tightly packed cells that line an organ, gland, duct, or body surface
Ingestion
The act of bringing food into the digestive tract
Microvillus
Tiny protrusions from the surface of an epithelial Cell that increases the surface area for absorption of substances
Nutrient
Any substance that an organism requires for normal growth, maintenance, or reproduction
Small intestine
Portion of digestive tract between stomach and large intestine (final stages of digestion and most nutrient absorption)
Sodium-potassium pump
Transmembrane protein that uses ATP to move sodium ions out of the cell and potassium ions into the cell (normally against gradient)
Symporters
Cotransport protein that allows an ion to diffuse down an electrochemical gradient using that energy to transport a different substance in the same direction against its concentration gradient
Villus
Small finger like projections of
-the lining of the small intestine
- of the fetal portion of the placenta
Oral rehydration therapy
Fluid replacement to prevent and treat dehydration
(Drinking water with some sugar and salts [sodium and potassium])