Cholesterol - Fat Transportation

Question 1

3 primary sources of fats

Answer 1

Diet

De novo biosynthesis (liver)

Storage depots in adipose

Question 2

Where are Bile salts generated and what did they do?

Answer 2

Generated in liver and stored in gallbladder

Digestion —> pass from bile duct into the intestines

Emulsify fats in intestine —> aid absorption of dats and fat soluble vitamins

Question 3

What does a lack of bile salts cause?

Answer 3

Majority of fat passes through gut undogested and unabsorbed —> steatorrhea

Question 4

What is Orlistat and what does it do?

Answer 4

Potent inhibitor of gastric and pancreatic lipases

Reduces fat absorption by 30% —> almost completely excreted by the faecal route

Trials have shown it is effective in treating obesity

Side effects: abdominal pain, urgency to defecate, increased flatus and steatorrhea

Question 5

How are lipids transported in the plasma?

Answer 5

Lipoproteins

Question 6

How are Chylomicrons formed?

Answer 6

Digested dietary products absorbed by entrocytes that line brush border of small intestines

Triglycerides resynthesised and incorporated into chylomicrions

Transported via lymphatics and into the bloodstream

Acquire apoproteins from HDL following release into bloodstream

Question 7

Lipoprotein lipase

Answer 7

Located ion capillary endothelial cells lining a variety of tissues (adipose, heart, skeletal muscle)

Cleaves chylomicrons