Digestive System and Nutrient Absorption

These flashcards cover key vocabulary and concepts related to the digestive system, the absorption of nutrients, and mechanisms involved in metabolism.

Nuclease

An enzyme secreted by the pancreas that breaks down nucleic acids.

Cotransport

A mechanism where one ion moves down its concentration gradient, using the energy of that movement to transport another substance into the cell.

Fructose

A monosaccharide that can diffuse directly into epithelial cells.

Symport

A type of cotransport where two substances are transported in the same direction across a membrane.

Micelles

Structures formed by bile that consist of phospholipids, used to transport nonpolar substances like lipids across membranes.

Phospholipid Bilayer

The structure of cell membranes, composed of polar heads facing outward and nonpolar tails facing inward.

Chylomicrons

Lipids packaged in proteins for transport through the lymphatic system.

Lacteals

Lymphatic capillaries in the villi that pick up lipids and facilitate their transport into the bloodstream.

Bile Salts

Compounds that emulsify fats, allowing for easier digestion and absorption of lipids.

Iron Ferritin Complex

A complex formed to store iron in the digestive tract until needed to prevent excessive blood iron levels.

Parathyroid Hormone

A hormone that regulates calcium absorption in the intestines and bone metabolism.

Endocytosis

A process where cells engulf large molecules, such as vitamin B12, for absorption.

Osmotic Pumps

Mechanisms that use ion transport to increase osmolarity, resulting in water movement across membranes.