Digestion and Absorption of Fats

Question 1

Give four examples of fat soluble vitamins

Answer 1

A, D, E, K

Question 2

Describe the structure of a triglyceride

Answer 2

Comprises 3 long chain fatty acids linked to a glycerol backbone by an ester linkage

Question 3

Give 3 examples of other lipids aside from triglycerides

Answer 3

Phospholipids
Cholesterol esters
Cholesterol

Question 4

Fats are immiscible in water, so how are they digested?

Answer 4

They are emulsified into small droplets by bile salts and amphipathic lipids

Question 5

What is the role of bile salts?

Answer 5

Bile salts solubilise the products of lipase digestion into micelles to facilitate uptake into enterocytes in the jejunum

Question 6

What class of enzymes degrade lipids?

Answer 6

Lipases

Question 7

What is the role of colipase?

Answer 7

Colipase prevents the association of pancreatic lipase with a now bile salt coated fat droplet

Question 8

What are the three broad classes of lipase

Answer 8

Lingual lipase
Gastric lipase
Pancreatic lipase

Question 9

Lingual lipase is released from where?

Answer 9

Ebner’s glands

Question 10

Which lipase is particularly important in neonates for milk digestion?

Answer 10

Gastric lipase

Question 11

What is the term for “greasy stools”?

Answer 11

Steatorrhea

Question 12

Which organ synthesises bile?

Answer 12

Liver

Question 13

Which organ stores and concentrates bile?

Answer 13

Gallbladder

Question 14

What are bile acids?

Answer 14

The breakdown products of cholesterol

Question 15

What are the primary bile acids? Give 2 examples

Answer 15

Cholic and chenodeoxycholic acid

Question 16

Describe the structure of bile acids

Answer 16

Planar structure, with all polar groups on one face and non-polar groups on the other face

Question 17

Most triacylglycerol degradation is incomplete, they are degraded into…?

Answer 17

2-monoacylglycerol

Question 18

Bile salts are not absorbed by the enterocytes with the products of fat digestion - so what happens?

Answer 18

They are transported to the ileum for reabsorption and recycling

Question 19

Chylomicrons are very big and hence cannot pass into capillaries. How do they hence enter circulation?

Answer 19

Thoracic lymph duct

Question 20

What does LCAT stand for?

Answer 20

Lecithin-cholesterol acyltransferase

Question 21

What is the difference between Omega-3 and Omega-6 fatty acids?

Answer 21

Omega-3: Anti-inflammatory

Omega-6: Pro-inflammatory