Lipids IV

Question 1

Degradation of glycosphingolipids

Answer 1

degradation of glycolipids requires sequential action of differnt glycosidases with high substrate specificity. Each bond requires a different enzyme which explains the different clinical presentaitions. Any defect in these enzymes will lead to accumulation of undegraded glycolipids in lysosomes

Question 2

Tay-Sachs Disease

Answer 2

gangliosides

Question 3

Caucher’s disease

Answer 3

glucocerebrosides

Question 4

Fabry Disease

Answer 4

Ceramide

Question 5

Neimann-Pick Disease

Answer 5

spingomylein

Question 6

Sandhoff disease

Answer 6

gnglio/globosides

Question 7

Metachromatic Leukodystrophy

Answer 7

sulfatides

Question 8

Rate limiting step of cholesterol synthesis

Answer 8

HMG-CoA is converted to Mevalonic acid via HMG-CpA reductase. requires 2 NADPH

Question 9

Presentation of Gaucher’s disease

Answer 9

absence of glucocerebrosidase leads to accumulation of glucocerebrosides in liver, spleen, CNS tissue, and bones

Question 10

Bile Acids

Answer 10

more hydrophobic than cholesterol

Question 11

Statubs

Answer 11

reduce HMG-CoA reductase activity, can reduce serum cholesterol by 50%

Question 12

Secretion of bile acids

Answer 12

secreted by liver through the bile duct into the GI tract and emulsify fat from diet

Question 13

Absorption of bile acids

Answer 13

Most excreted bile acids are later re-absorbed through the intrahepatic circulation

Question 14

Gallstone formation

Answer 14

Cholesterol concentration gets too high, the compound begins to precipitate and form cholesterol stores. When stones reach a certain size, they obstruct the gall duct and cause a painful backup of bile