Lipid Digestion

Question 1

Where is the only place lipid digestion occurs?

Answer 1

Lumen of the ileum - small intestines

Question 2

Where is bile produced and stored?

Answer 2

Produced in the liver and stored in the gallbladder

Question 3

Examples of lipids

Answer 3

-Red meats
-Dairy products
-Oils e.g. olive oil

Question 4

Process of lipid digestion

Answer 4

1) Lipid droplets are mixed with bile salts to form smaller emulsified droplets to increase surface area for faster hydrolysis by lipase
2) Triclyercides hydrolysed into glycerol, fatty acids and monoglycerides
3) Bile salts, glycerol and fatty acids combine to form micelles
5) Micelles make the fatty acids soluble in water and bring them to the surface of the epithelial cell membrane, this maintains a higher concentration relative to the epithelial cells

Question 5

Process of lipid absorption

Answer 5

6) Fatty acids enter the epithelial cell by simple diffusion but micelles don’t cross the membrane
7) At the smooth endoplamsic reticulum, fatty acids and glycerol are recombined to form triglycerides
8) At the Golgi apparatus, triglycerides are modified, proteins are added to form lipoproteins known as chylomicrons then packaged into vesicles. They are water soluble so can be carried in the body
9) Chylomicrons are transported into a lymph vessel by exocytosis, then they enter the blood