Fat Digestion Flashcards
(11 cards)
What are three fatty acids that we absorb and need?
Linoleic acid (polyunsaturated), stearic acid (saturated) and oleic acid (monounsaturated)
What are the physical properties of saturated fats?
Solid at room temperature
More resistant to oxidation
What are the physical properties of unsaturated fats?
Monounsaturated is slightly less susceptible to spoilage than polyunsaturated fats
Polyunsaturated fats are liquid at room temperature
Can hydrogenate to make last longer however alters the texture
What are sterols, how are the obtained and what do they do?
Ring like structures, such as cholesterol found in animal foods (meats, eggs, dairy). (NB plant based sterols can interfere with cholesterol ansorption)
They acts as percursors for bile, hormones and vitamin D and act as a component of cell walls
Where does fat digestion begin?
In the mouth due to slaivary glands producing lingual lipse
How is at digested in the stomach?
Acid stable lingual lipase breaks down fats
Muscle movements of the stomach moves contents around
Gastric lipase breaks down fats
What happens on the duodenum?
Cholecystokinin signals the gall bladder to release bile
Bile emulsifies the fats
Emulsified fats are broken down by pancreatic and intestinal lipase AND pancreatic cholesterolesterase
Why is fat sometimes found in faeces?
Fibre traps fat and cholesterol sometimes
How is fat absorbed?
Small/medium fatty acids and glycerol are absorbed straight into the bloodstream
Larger fatty acids and triglycerides are absorbed aided by bile, and then sorted into chylomicrons where they are transported in the lymph.
How is fat transported?
Chylomicrons, in the bloodstream, become smaller due to lipases in peripheral tiisues and are eventually endocytosed in the liver, where remaining lipid is turned and packaged into:
VLDL- mainly triglyceride
LDL-mainly cholesterol
HDL- mainly protein
What is the recommended dietary intake of fat?
fat intake should be 20-35% of total energy inatke
