Digestion and Absorption of Fats Flashcards
Give four examples of fat soluble vitamins
A, D, E, K
Describe the structure of a triglyceride
Comprises 3 long chain fatty acids linked to a glycerol backbone by an ester linkage
Give 3 examples of other lipids aside from triglycerides
Phospholipids
Cholesterol esters
Cholesterol
Fats are immiscible in water, so how are they digested?
They are emulsified into small droplets by bile salts and amphipathic lipids
What is the role of bile salts?
Bile salts solubilise the products of lipase digestion into micelles to facilitate uptake into enterocytes in the jejunum
What class of enzymes degrade lipids?
Lipases
What is the role of colipase?
Colipase prevents the association of pancreatic lipase with a now bile salt coated fat droplet
What are the three broad classes of lipase
Lingual lipase
Gastric lipase
Pancreatic lipase
Lingual lipase is released from where?
Ebner’s glands
Which lipase is particularly important in neonates for milk digestion?
Gastric lipase
What is the term for “greasy stools”?
Steatorrhea
Which organ synthesises bile?
Liver
Which organ stores and concentrates bile?
Gallbladder
What are bile acids?
The breakdown products of cholesterol
What are the primary bile acids? Give 2 examples
Cholic and chenodeoxycholic acid
Describe the structure of bile acids
Planar structure, with all polar groups on one face and non-polar groups on the other face
Most triacylglycerol degradation is incomplete, they are degraded into…?
2-monoacylglycerol
Bile salts are not absorbed by the enterocytes with the products of fat digestion - so what happens?
They are transported to the ileum for reabsorption and recycling
Chylomicrons are very big and hence cannot pass into capillaries. How do they hence enter circulation?
Thoracic lymph duct
What does LCAT stand for?
Lecithin-cholesterol acyltransferase
What is the difference between Omega-3 and Omega-6 fatty acids?
Omega-3: Anti-inflammatory
Omega-6: Pro-inflammatory
