Structure Of Lipids And Lipid Metabolism

Question 1

The only classes of FA that is an exception to the chylomicron-mediated transportation of fatty acids from the intestines to the circulation

Answer 1

Short chain FA (SCFA)
Medium chain FA (MCFA)

Question 2

What type of fatty acid serves as an important source of energy for the colonic mucosa?

Answer 2

Short chain fatty acids (SCFA)

Question 3

What is a semi-essential fatty acid derived from linoleic acid?

Answer 3

Arachidonic acid

Question 4

Which class of fatty acids can decrease the risk for cardiovascular disease (CVD) and reduce platelet aggregation?

Answer 4

Omega-3 fatty acids

Question 5

Which fatty acid is important for the development of the fetal brain and retina?

Answer 5

Cervonic acid (docosahexaenoic acid, DHA)

Question 6

What serves as the main storage form of lipids in the body?

Answer 6

Triacylglycerol

Question 7

Which lipoprotein has the largest diameter, lowest density, and highest TAG content?

Answer 7

Chylomicron

Question 8

Which lipoprotein has the highest cholesterol content?

Answer 8

Low-Density Lipoprotein (LDL)

Question 9

Which lipoprotein has the highest protein content?

Answer 9

High-Density Lipoprotein (HDL)

Question 10

What is an important steroid in animal cell membranes?

Answer 10

Cholesterol

Question 11

What is an important steroid in fungal cell membranes?

Answer 11

Ergosterol

Question 12

What is the storage form of cholesterol?

Answer 12

Cholesteryl esters

Question 13

What are primary bile acids synthesized by?

Answer 13

The liver

Question 14

What are secondary bile acids resulting from?

Answer 14

Bacterial degradation in the colon

Question 15

What enzyme is responsible for converting androgens to estrogens?

Answer 15

Aromatase

Question 16

Secondary bile acids resulting from bacterial degradation in the colon

Answer 16

Cholic acid → Deoxycholic acid
Chenodeoxycholic acid → Lithocholic acid

Question 17

Primary bile acids synthesized by the liver

Answer 17

Cholic acid

Chenodeoxycholic acid

Question 18

Essential fatty acids

Answer 18

Linoleic acid
a-Linolenic acid

Question 19

Activation of fatty acids into acyl coenzyme A (acyl-CoA) occurs mainly in which cellular compartment?

Answer 19

Cytosol

Question 20

What is the sequence of steps repeated in the process of lipogenesis?

Answer 20

Condensation → Reduction → Dehydration → Reduction

Question 21

What is the sequence of steps repeated in the process of beta-oxidation of fatty acids?

Answer 21

Oxidation → Hydration → Oxidation → Thiolysis

Question 22

Where does beta-oxidation of fatty acids occur?

Answer 22

Mitochondria

Question 23

Where does the oxidation of very long chain fatty acids take place?

Answer 23

Peroxisomes

Question 24

What is the most common inborn error of fatty acid oxidation?

Answer 24

Medium-chain fatty acyl CoA dehydrogenase (MCAD) deficiency

Question 25

This condition occurs due to the consumption of unripe fruit of the akee tree due to the toxin hypoglycin that inactivates medium- and short-chain acyl-CoA dehydrogenase, inhibiting B- oxidation and causing hypoglycemia

Answer 25

Jamaican vomiting sickness

Question 26

What leads to the accumulation of phytanic acid?

Answer 26

Deficiency of phytanoyl-CoA hydroxylase.

Question 27

What results from inherited absences of peroxisomes in all tissues?

Answer 27

Marked accumulation of very-long-chain, saturated, unbranched fatty acids in liver and central nervous system.

Question 28

What causes the accumulation of VLCFAs in the brain, adrenals, and testes?

Answer 28

Inability to transport VLCFAs across the peroxisomal membrane.

Question 29

What type of disorder is cystic fibrosis?

Answer 29

Autosomal recessive disorder due to mutations in the CFTR gene.

Question 30

What value of sweat chloride may be used to diagnose cystic fibrosis?

Answer 30

Sweat chloride >60 mmol/L.

Question 31

What is the result of 7-dehydrocholesterol reductase deficiency?

Answer 31

Low plasma cholesterol and elevated 7-dehydrocholesterol.

Question 32

What is the most common form of congenital adrenal hyperplasia?

Answer 32

21-alpha-hydroxylase deficiency.

Question 33

Refers to the autoimmune destruction of the adrenal cortex leading to adrenocortical insufficiency?

Answer 33

Addison Disease

Question 34

What is the lipoprotein with the largest diameter, lowest density, and highest triacylglycerol content?

Answer 34

Chylomicron.

Question 35

What lipoprotein has the highest cholesterol content?

Answer 35

LDL.

Question 36

What lipoprotein has the highest protein content?

Answer 36

HDL.

Question 37

What is the cofactor of lecithin: cholesterol acyltransferase?

Answer 37

Apolipoprotein A-1.

Question 38

What mediates assembly and secretion of VLDL?

Answer 38

Apolipoprotein B-100.

Question 39

What is the main apoprotein that mediates secretion of chylomicrons from small intestines?

Answer 39

Apolipoprotein B-48.

Question 40

What is the cofactor of lipoprotein lipase?

Answer 40

Apolipoprotein C-II.

Question 41

What mediates uptake of chylomicron remnants?

Answer 41

Apolipoprotein E.

Question 42

What is Refsum disease?

Answer 42

A genetic disorder leading to phytanic acid accumulation.

Question 43

What is Zellweger syndrome?

Answer 43

A disorder caused by peroxisome biogenesis defects.

Question 44

What is Adrenoleukodystrophy?

Answer 44

A disorder affecting the metabolism of very-long-chain fatty acids.

Question 45

What is cystic fibrosis?

Answer 45

A genetic disorder affecting the respiratory and digestive systems.

Question 46

What are the products of ketogenesis?

Answer 46

Acetoacetate, B-hydroxybutyrate, Acetone.

Question 47

What is Smith-Lemli-Opitz syndrome?

Answer 47

A genetic disorder caused by 7-dehydrocholesterol reductase deficiency.

Question 48

What is Addison disease?

Answer 48

A condition resulting from adrenocortical insufficiency.