BOWE 253 Lipid Metabolism MSC PBL WORK BOOK with
Accurate Answers Module 5 Complete A+ Graded
What are the functions of lipids? - answer1- Major source of energy
2- Major component of cell membranes
3- Biosynthetic precursors
4- Cell signalling (prostaglandins & steroid hormones)
5- Facilitate absorptions of fat-soluble vitamins (eg. A,E,D,K)
6- Protections & insulation
What is the first step of lipid metabolism? - answerDigestion
At which sites of the body can lipids be digested? - answer1- Mouth
2- Stomach
3- Small intestines
What enzyme is involved in the digestion of lipids in the mouth? - answerLingual lipase
What enzyme is involved in the digestion of lipids in the stomach? - answerGastric lipase
,What substance and enzyme are involved in the digestion of lipids in the small intestines? - answer1-
Bile salts
2- Pancreatic lipase
At the small intestines, what does the substance, bile salts, do to the lipids? - answerLipids are
emulsified by the bile salts
Why are lipids emulsified by the bile salts first at the small intestine? - answerTo increase the surface
area, upon which the enzyme, pancreatic lipase, can work on
What does the pancreatic lipase do to the emulsified lipids at the small intestine? - answerPancreatic
lipase can further breakdown (hydrolyse) the emulsified lipids, eg. triglycerides
Where are the bile salts stored? - answerIn the gallbladder
From where is the pancreatic lipase released? - answerPancreas
What is the function of the hormone, cholecystokinin (CCK)? - answerWhen food enters the small
intestine, CCK signals the release of pancreatic lipase and the contraction of the gallbladder, by which
bile salts can be released to emulsify the lipids.
What are the products of digestion/ hydrolysis of triglycerides? - answer1- Fatty acids (3 molecules)
2- Glycerol (1 molecule)
After the breakdown of triglycerides, what is the next step? - answerAbsorption of lipids
What is the first step of lipid absorption? - answer1- Fatty acids and glycerol are emulsified by bile salts
to form micelles
2- Micelles travel through layer of water and enter intestinal epithelial cells
3- At intestinal epithelial cells, fatty acids and glycerol undergo enzymatic reaction at SER, to form
triglycerides
, 4- Triglycerides are combined with proteins at the Golgi apparatus to form chylomicrons (lipoprotein
particles)
5- Chylomicrons enter the lacteal (lymph vessels of small intestine) and are transported away from
intestines
What are chylomicrons? - answerLipoprotein particles
What is the nature of chylomicrons? - answerAmphipathic - polar and non polar
What is the function of chylomicrons? - answerTo transport digested lipids (in the form of recombined
triglycerides) in circulatory system and enter adipose and other tissues
Which step, in lipid metabolism, does lipid absorption fall under? - answer2nd step
What is the nature of lipids? - answerHydrophobic
Due to their hydrophobic nature, how are lipids transported? - answerThe lipids, triglycerides (TAG) and
cholesterol, require special transport proteins = lipoproteins
What are some examples of lipoproteins? - answer1- Chylomicrons
2- Very low density lipoproteins (VLDL)
3- Low density lipoproteins (LDL)
Where do chylomicrons transport lipoproteins? - answerFrom small intestine to rest of the body
What do VLDL carry/ transport? - answerSynthesised TAG
What do LDL carry/ transport? - answerCholesterol
Where do LDL carry/transport cholesterol to? - answerPeripheral tissues
Accurate Answers Module 5 Complete A+ Graded
What are the functions of lipids? - answer1- Major source of energy
2- Major component of cell membranes
3- Biosynthetic precursors
4- Cell signalling (prostaglandins & steroid hormones)
5- Facilitate absorptions of fat-soluble vitamins (eg. A,E,D,K)
6- Protections & insulation
What is the first step of lipid metabolism? - answerDigestion
At which sites of the body can lipids be digested? - answer1- Mouth
2- Stomach
3- Small intestines
What enzyme is involved in the digestion of lipids in the mouth? - answerLingual lipase
What enzyme is involved in the digestion of lipids in the stomach? - answerGastric lipase
,What substance and enzyme are involved in the digestion of lipids in the small intestines? - answer1-
Bile salts
2- Pancreatic lipase
At the small intestines, what does the substance, bile salts, do to the lipids? - answerLipids are
emulsified by the bile salts
Why are lipids emulsified by the bile salts first at the small intestine? - answerTo increase the surface
area, upon which the enzyme, pancreatic lipase, can work on
What does the pancreatic lipase do to the emulsified lipids at the small intestine? - answerPancreatic
lipase can further breakdown (hydrolyse) the emulsified lipids, eg. triglycerides
Where are the bile salts stored? - answerIn the gallbladder
From where is the pancreatic lipase released? - answerPancreas
What is the function of the hormone, cholecystokinin (CCK)? - answerWhen food enters the small
intestine, CCK signals the release of pancreatic lipase and the contraction of the gallbladder, by which
bile salts can be released to emulsify the lipids.
What are the products of digestion/ hydrolysis of triglycerides? - answer1- Fatty acids (3 molecules)
2- Glycerol (1 molecule)
After the breakdown of triglycerides, what is the next step? - answerAbsorption of lipids
What is the first step of lipid absorption? - answer1- Fatty acids and glycerol are emulsified by bile salts
to form micelles
2- Micelles travel through layer of water and enter intestinal epithelial cells
3- At intestinal epithelial cells, fatty acids and glycerol undergo enzymatic reaction at SER, to form
triglycerides
, 4- Triglycerides are combined with proteins at the Golgi apparatus to form chylomicrons (lipoprotein
particles)
5- Chylomicrons enter the lacteal (lymph vessels of small intestine) and are transported away from
intestines
What are chylomicrons? - answerLipoprotein particles
What is the nature of chylomicrons? - answerAmphipathic - polar and non polar
What is the function of chylomicrons? - answerTo transport digested lipids (in the form of recombined
triglycerides) in circulatory system and enter adipose and other tissues
Which step, in lipid metabolism, does lipid absorption fall under? - answer2nd step
What is the nature of lipids? - answerHydrophobic
Due to their hydrophobic nature, how are lipids transported? - answerThe lipids, triglycerides (TAG) and
cholesterol, require special transport proteins = lipoproteins
What are some examples of lipoproteins? - answer1- Chylomicrons
2- Very low density lipoproteins (VLDL)
3- Low density lipoproteins (LDL)
Where do chylomicrons transport lipoproteins? - answerFrom small intestine to rest of the body
What do VLDL carry/ transport? - answerSynthesised TAG
What do LDL carry/ transport? - answerCholesterol
Where do LDL carry/transport cholesterol to? - answerPeripheral tissues
