Nutrient Absorption Flashcards
(12 cards)
What is Nutrient Absorption?
Nutrient absorption is the final step in the digestive process that allow the body to absorb components needed for energy, growth and repair. Nutrients are taken from the digestive system and into the bloodstream and lymphatic system. Each macromolecule has its own pathway during nutrient absorption.
What are Macromolecules?
Macromolecules are molecules composed of small subunits called monomers. They are needed in large amounts and are essential to life.
What are the Four Macromolecules?
Carbohydrates
Proteins
Lipids
Nucleic Acids
Villi
Finger like structures that line the internal walls of the small intestine.
What is the Function of Villi?
Villi contain microvilli, maximizing surface area for efficient absorption. Inside the villi are capillary beds that allow nutrient absorption to occur. Surrounded by the capillary beds are the lacteal.
Carbohydrate Absorption
Monosaccharides are absorbed through the intestinal cells of the villi and enter the blood stream through active transport.
What is Broken Down During Carbohydrate Absorption?
Polysaccharides are broken down by enzymes to disaccharides and eventually monosaccharides.
What is the Pathway for Carbohydrate Digestion, and What Enzymes are Used?
Carbohydrate digestion begins in the mouth, where salivary amylase enzymes break down starch, also know as polysaccharides, into maltose, a type of disaccharide. As chyme enters the small intestine, pancreatic amylase, released from the pancreas further breaks down the remaining starch into disaccharides. Once broken down, carbohydrase enzymes, found in the lining of the small intestine, break the disaccharides down into monosaccharides, allowing it to be absorbed into the bloodstream.
Protein Absorption
Also known as amino acid absorption. Amino acids are absorbed through the intestinal cells of the villi and enter the bloodstream through active transport.
What is Broken Down During Protein Absorption?
Protein, also known as polypeptides, is broken down by enzymes into peptides, and eventually into amino acids.
What is the Pathway for Protein Digestion, and What Enzymes are Used?
Protein digestion begins in the stomach by an acidic enzyme called pepsin, that breaks protein into peptides. Digestion continues in the small intestine by proteases trypsin and chymotrypsin that further break down peptides into amino acids, which are then absorbed into the bloodstream.
Where do Amino Acids go After Being Absorbed Into the Bloodstream?
The liver.
