Nutrient Digestion II - Fats, Vitamins and Minerals Flashcards
In what form is almost all fat ingested as?
Triacylglycerides
What molecule is responsible for fat digestion in the small intestine?
Pancreatic lipases
How do TAGs present in water?
Large lipid droplets
Digestion can only take place at what point on a lipid droplet? What implication does this have on speed of digestion?
The surface (interface) therefore digests very slowly
What process helps to speed up digestion and uptake of lipids from small intestine?
Emulsification
What two steps occur in the emulsification process?
Mechanical disruption and emulsification
How is mechanical disruption of lipid droplets achieved?
Smooth muscle contraction grinds and mixes lumenal contents
What emulsifier is used to break up lipid droplets?
Bile (mixture of bile salts and phospholipids)
What is an amphipathic molecule?
A molecule with both polar and non-polar regions
The formation of smaller conglomerate molecules also help speed up monoglyceride digestion. What are these molecules called?
Micelles
What are micelles comprised of?
Monoglycerides
Bile salts
Phospholipids
Fatty acid
After crossing into the intestinal epithelial cells, what is the fate of free fatty acids?
They are reformed into TAGs in the smooth endoplasmic reticulum and covered in amphipathic proteins
What organelle facilitates the transport of TAGs in the epithelial cells?
Golgi Apparatus
What are extracellular fat droplets called after they have been absorbed?
Chylomicrons
What are chylomicrons comprised of?
Phospholipids, cholesterol, fat soluble vitamins