FA Metabolism - Notes

Question 1

Examples of lipids

Answer 1

TAG, FAs, Cholesterol, phospholipids, glycolipids

• water-insoluble
• transported in droplets; with albumin; or as constituents of lipoprotein particles

Question 2

What is the rate of acid-stable lipase?

Answer 2

slow hydrolysis bc ingests TAGs form a separate lipid phase with limited water-lipid interface

Question 3

What can hydrolyze TAG molecules containing short or long chain FAs?

Answer 3

gastric lipase (optimally active at neutral pH, so of little use in adult stomach where pH is low, but is useful in neonate)

Question 4

What two hormones control the release of pancreatic enzymes?

Answer 4

• cholecystokinin;

- secretin

Question 5

Cholecystokinin

Answer 5

secreted by epithelial endocrine cells of SI (stimulated by luminal AAs, FAs, and acidic pH)

stimulates gall bladder contraction; causes decreased gastric motilitiy;

*ACTIVATES PANCREATIC PHOSPHATIDYLIONOSITOL TRIPHOSPHATE PATHWAY

Question 6

SECRETIN

Answer 6

released by endocrine cells of SI with luminal pH

Question 7

How is dietary TAG degraded?

Answer 7

pancreatic lipase: preferentially removes FAs at C1 and C3 leaving 2-monoacylglycerol