HNE25306
Problem set 3: Lipids and Lipids & Health
Instructor: Sander Kersten
Lipids
1. About 95% of the lipids in the diet are ______________. The remaining 5% consists
of _________ and _____________. Triglycerides are composed of _________ with ___
fatty acids attached. The fatty acids may be classified as _____________,
monounsaturated, or polyunsaturated.
2. What features distinguish fatty acids from each other?
3. What is the name of the most important enzyme involved in the breakdown of dietary
triglycerides ?
4. What is the generic name of the following fatty acids:
a) C18:3 n-3
b) C14:0
c) C18:1 n-9
d) C18:0
e) C16:0
f) C22:6 n-3
g) C18:2 n-6
5. When bile ducts are blocked (called cholestasis), bile acids cannot be delivered into the
intestine and accumulate in the blood. What would be the impact in the small intestine?
6. Explain the difference between the n- (or ) nomenclature and the -nomenclature of
double bonds in fatty acids.
7. Why are triglycerides, unlike glucose, not freely circulating in blood plasma?
8. Have you ever had blood withdrawn shortly after a (fatty) meal? What is typical for
blood plasma taken from subjects that just consumed a high fat meal? Why is this?
9. Explain what happens to dietary fat once it is absorbed in the intestinal cell.
10. Name some vegetable oils that are very high in saturated fatty acids. Same for poly-
unsaturated fatty acids.
11. Fish oil is very rich in -3 fatty acids of carbon chain length 20 and 22 (EPA 20:5
and DHA 22:6). What is the origin of these fatty acids? In the human body DHA is
concentrated in certain anatomical locations. Name one.
12. Explain the role of bile in fat digestion using the chemical composition of bile acids.
, 13. The human body (mainly liver) is able to carry out all kinds of fatty acid elongation
and desaturation reactions, adding carbons and double bonds to fatty acids. Why is it that
we still require certain fatty acids in our diet, which are called essential fatty acids?
14. What are the particles called that carry dietary triglycerides in the blood? What else
besides triglycerides do they consist of?
15. What enzyme is required to move triglycerides in the blood to the adipose tissue?
Where is it produced and where is it located?
16.
a) Name some foods that are high in cholesterol.
b) Which type of foods are devoid of cholesterol?
c) Should cholesterol be considered as a nutrient? Explain.
d) Name two roles of cholesterol in the body.
e) What are the names of cholesterol equivalent in plants?
f) How do these compounds interact with cholesterol in the gut?
17. A biopsy of our adipose tissue can be collected for determination of the fatty acid
composition. What could be the purpose of this type of analysis?
Lipids and Health
1. Mention several risk factors for cardiovascular disease.
2. Your blood was tested for cholesterol after you complained of severe pain in your
chest. Your total plasma cholesterol level was 3.7 mM and your HDL level was 1.42
mM. Should you be worried ?
Problem set 3: Lipids and Lipids & Health
Instructor: Sander Kersten
Lipids
1. About 95% of the lipids in the diet are ______________. The remaining 5% consists
of _________ and _____________. Triglycerides are composed of _________ with ___
fatty acids attached. The fatty acids may be classified as _____________,
monounsaturated, or polyunsaturated.
2. What features distinguish fatty acids from each other?
3. What is the name of the most important enzyme involved in the breakdown of dietary
triglycerides ?
4. What is the generic name of the following fatty acids:
a) C18:3 n-3
b) C14:0
c) C18:1 n-9
d) C18:0
e) C16:0
f) C22:6 n-3
g) C18:2 n-6
5. When bile ducts are blocked (called cholestasis), bile acids cannot be delivered into the
intestine and accumulate in the blood. What would be the impact in the small intestine?
6. Explain the difference between the n- (or ) nomenclature and the -nomenclature of
double bonds in fatty acids.
7. Why are triglycerides, unlike glucose, not freely circulating in blood plasma?
8. Have you ever had blood withdrawn shortly after a (fatty) meal? What is typical for
blood plasma taken from subjects that just consumed a high fat meal? Why is this?
9. Explain what happens to dietary fat once it is absorbed in the intestinal cell.
10. Name some vegetable oils that are very high in saturated fatty acids. Same for poly-
unsaturated fatty acids.
11. Fish oil is very rich in -3 fatty acids of carbon chain length 20 and 22 (EPA 20:5
and DHA 22:6). What is the origin of these fatty acids? In the human body DHA is
concentrated in certain anatomical locations. Name one.
12. Explain the role of bile in fat digestion using the chemical composition of bile acids.
, 13. The human body (mainly liver) is able to carry out all kinds of fatty acid elongation
and desaturation reactions, adding carbons and double bonds to fatty acids. Why is it that
we still require certain fatty acids in our diet, which are called essential fatty acids?
14. What are the particles called that carry dietary triglycerides in the blood? What else
besides triglycerides do they consist of?
15. What enzyme is required to move triglycerides in the blood to the adipose tissue?
Where is it produced and where is it located?
16.
a) Name some foods that are high in cholesterol.
b) Which type of foods are devoid of cholesterol?
c) Should cholesterol be considered as a nutrient? Explain.
d) Name two roles of cholesterol in the body.
e) What are the names of cholesterol equivalent in plants?
f) How do these compounds interact with cholesterol in the gut?
17. A biopsy of our adipose tissue can be collected for determination of the fatty acid
composition. What could be the purpose of this type of analysis?
Lipids and Health
1. Mention several risk factors for cardiovascular disease.
2. Your blood was tested for cholesterol after you complained of severe pain in your
chest. Your total plasma cholesterol level was 3.7 mM and your HDL level was 1.42
mM. Should you be worried ?
