PHOSPHOLIPID, GLYCOSPHINGOLIPID, AND EICOSANOID METABOLISM

Question 1

are a class of lipids that are essential components of cell membranes.
They are amphipathic molecules.
Major components of biological membranes

Answer 1

Phospholipids

Question 2

Two classes of phospholipids:

Answer 2

Glycerophospholipids
Sphingophospholipids

Question 3

(contain glycerol backbone)

Answer 3

Glycerophospholipids

Question 4

(contain sphingosine)

Answer 4

Sphingophospholipids

Question 5

Serine + PA →

Answer 5

phosphatidylserine (PS)

Question 6

Ethanolamine+PA→

Answer 6

phosphatidylethanolamine (PE) (cephalin)

Question 7

Choline + PA →

Answer 7

phosphatidylcholine (PC) (lecithin)

Question 8

Inositol + PA →

Answer 8

phosphatidylinositol (PI)

Question 9

Glycerol + PA →

Answer 9

phosphatidylglycerol (PG)

Question 10

an important component of myelin that protects and insulates nerve fibers

Answer 10

Sphingomyelin

Question 11

are a major component of lung surfactant

Answer 11

Phospholipids

Question 12

a phospholipid that is found in relatively large amounts in mitochondrial membranes.

is a precursor of cardiolipin, a phospholipid that is unique to mitochondria

Answer 12

Phosphatidylglycerol

Question 13

Phosphatidylserine (PS) is synthesized from phosphatidylethanolamine (PE) and free serine in a base exchange reaction catalyzed by the enzyme ___

Answer 13

phosphatidylserine synthase.

Question 14

Defects in phospholipid synthesis can lead to a variety of diseases, including

Answer 14

respiratory distress syndrome (RDS)

acute respiratory distress syndrome (ARDS)

Question 15

Phosphoglycerides are degraded by ___, a group of enzymes that hydrolyze the phosphodiester bonds of phosphoglycerides.

Answer 15

phospholipases

Question 16

Phospholipases are also responsible for ___, which is a process of removing and replacing fatty acids on phospholipids.

Answer 16

remodeling phospholipids

Question 17

Sphingomyelin is degraded by __

Answer 17

sphingomyelinase

Question 18

a lysosomal enzyme that hydrolyzes the phosphodiester bond between the phosphate group and the choline group on sphingomyelin.

Answer 18

sphingomyelinase

Question 19

is a lysosomal storage disease caused by a deficiency of sphingomyelinase.

Answer 19

Niemann-Pick disease

Question 20

most severe form of the disease and is characterized by rapid and progressive neurodegeneration.

Answer 20

Type A Niemann-Pick disease

Question 21

less severe and does not cause damage to the nervous system.

Answer 21

Type B Niemann-Pick disease

Question 22

are molecules that contain both carbohydrate and lipid components.
They are derivatives of ceramides.
Act as: Blood group antigens, cell surface receptors for bacteria/viruses

Answer 22

Glycolipids

Question 23

are composed of a ceramide backbone and a carbohydrate head group

Answer 23

Glycosphingolipids

Question 24

Glycosphingolipids TYPES

Answer 24

Neutral glycosphingolipids
Acidic glycosphingolipids

Question 25

do not have a net charge at physiological pH.

Answer 25

Neutral glycosphingolipids

Question 26

have a net negative charge at physiological pH.

Answer 26

Acidic glycosphingolipids

Question 27

____ are the most complex acidic glyco- sphingolipids. They contain one or more sialic acid residues attached to the carbohydrate head group.

Answer 27

Gangliosides

Question 28

These are a group of genetic disorders in which glycosphingolipids accumulate in cells and tissues.

Answer 28

Lipid storage disorders:

Question 29

Glycosphingolipids are thought to play a role in the development of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease.

Answer 29

Neurodegenerative diseases

Question 30

Cancer: ___ can be used as tumor markers to diagnose and monitor cancer.

Answer 30

Glycosphingolipids

Question 31

Synthesis of glycosphingolipids: occurs primarily in the

Answer 31

Golgi apparatus.

Question 32

___ can recognize both glycosphingolipids and glycoproteins as substrates.

Answer 32

Glycosyltransferases

Question 33

Glycosphingolipids are degraded in ___.

Answer 33

lysosomes

Question 34

are organelles that contain enzymes that can break down a variety of molecules.

Answer 34

Lysosomes

Question 35

can lead to lysosomal storage diseases.

Answer 35

Defects in glycosphingolipid degradation

Question 36

are a group of genetic disorders in which specific molecules accumulate in cells due to deficiencies in lysosomal enzymes

Answer 36

Lysosomal storage diseases

Question 37

It is caused by a deficiency of the enzyme hexosaminidase A, which breaks down the molecule GM2 ganglioside.

typically appear in the first few months of life and include blindness, deafness, seizures, and muscle weakness.

Answer 37

Tay-Sachs disease

Question 38

It is caused by a deficiency of the enzyme hexosaminidase A and B.

Symptoms: similar to those of Tay-Sachs disease, but they typically appear earlier in life and are more severe.

Answer 38

Sandhoff disease:

Question 39

This is a genetic disorder that affects the way the body metabolizes fat. It is caused by a deficiency of the enzyme glucocerebrosidase, which breaks down the molecule glucocerebroside.

symptoms, including hepatosplenomegaly (enlargement of the liver and spleen), skeletal deformities, and bleeding disorders

Answer 39

Gaucher disease

Question 40

It is caused by a deficiency of the enzyme galactocerebrosidase, which breaks down the molecule galactocerebroside.
Symptoms: typically appear in the first few months of life and include irritability, stiffness, seizures, and developmental delays.

Answer 40

Krabbe disease

Question 41

This is a group of genetic disorders that affect the way the body metabolizes cholesterol. It is caused by a deficiency of one of several enzymes that break down cholesterol and other lipids.

Answer 41

Niemann-Pick disease

Question 42

This is a rare genetic disorder that is X-linked, meaning that it affects males more often than females. It is caused by a deficiency of the enzyme alpha-galactosidase A, which breaks down the molecule globotriaosylceramide (Gb3)

symptoms, including a redpurple skin rash, kidney and heart failure, and burning pain in the extremities

Answer 42

Fabry disease

Question 43

It is caused by a deficiency of one of several enzymes that break down the molecule sulfatides. Sulfatides build up in the myelin sheath, which is the protective coating that surrounds nerve fibers.

Answer 43

Metachromatic leukodystrophy

Question 44

Disorfer that affects the way the body metabolizes ceramides. It is caused by a deficiency of the enzyme acid ceramidase, which breaks down ceramides.

symptoms, including painful and progressive joint deformity, subcutaneous nodules of lipid-laden cells, and a hoarse cry.

Answer 44

Farber disease

Question 45

are a class of signaling molecules derived from arachidonic acid. They are produced by a variety of enzymes, including cyclooxygenases (COX-1 and COX-2), lipoxygenases (LOXs), and epoxygenases.

Answer 45

Eicosanoids

Question 46

The first step in the synthesis of prostaglandins and thromboxanes is the conversion of arachidonic acid to prostaglandin endoperoxide H2 (PGH2) by __

Answer 46

COX-1 or COX-2.

Question 47

family of lipid mediators that promote platelet aggregation and vasoconstriction.

Answer 47

Thromboxanes

Question 48

The most important thromboxane is ___ it is produced by activated platelets and plays a key role in blood clot formation

Answer 48

thromboxane A2 (TXA2). TXA2

Question 49

are a family of lipid mediators that play a role in inflammation and allergic reactions.

Answer 49

Leukotrienes

Question 50

are a family of lipid mediators that play a role in a wide range of physiological and pathophysiological processes.

Answer 50

Prostaglandins