Initial lipid digestion Flashcards
What is the most common lipid molecule?
FAs
What can be generated as a result of the metabolism of FAs
ATP
What % of calories are from FAs?
30-40%
What are the three main sources of FAs?
Diet, Adipose tissue, De novo synthesis
What is de novo synthesis?
Making FAs from non-lipid precursors
What are some molecules used in de novo synthesis?
Carbohydrates, AAs and CO2
Where does fat digestion begin?
Small intestine
Which three organs are involved in fat digestion?
Small intestine, liver and pancreas
Which organ produces and releases bile?
Liver
Which organ does the liver release bile via?
Gall Bladder
What are the two main compounds that bile contains?
Bile acids and bile salts
What do bile salts and acids act as?
Detergents
What are bile salts and acids derived from?
Cholesterol
How do bile salts and acids act as detergents?
They emulsify the lipids
What is formed as a result of bile’s association with lipids?
Small droplets of fat
What does the pancreas produce?
Digestive enzymes and bicarbonate solution
What are the enzymes involved in fat digestion called?
Lipases
What is the name of the droplets formed as a result of the association between the nile salts and lipid droplets?
Micelles
What are the micelles met with before the fats enter the epithelial cells lining the small intestine?
pancreatic lipase
What does pancreatic lipase do?
Catalyses the hydrolysis of triacylglycerols
What are the products of the hydrolysis of triacylglycerols with pancreatic lipase?
2 acylglycerol and two fatty acids
What % of dietary fat is triacylglycerol?
95
What are the products of the first hydrolysis reaction of triacylglycerol?
1,2-diacylglycerol and a fatty acid
What are the products of the hydrolysis of 1,2-diacylglycerol?
2-acylglycerol and a fatty acid
Where is triacylglycerol lipase found?
At the water-lipid interface
What diffuses into the intestinal epithelial cells after the hydrolysis of triacylglycerol?
2-acylglycerol and two FAs
What is the role of phospholipase A2?
Acts upon phospholipids by removal of the FA residue at position C2
What does the removal of a fatty acid from position C2 from a phospholipid do?
Aids their digestion
What diffuses into the intestinal epithelial cells after the action of phospholipase A2?
A lysophospholipid and a FA
