BMB 401Summer 2007
EXAM 5 study aid for the final
1.Which of these is implicated in the recessive, fatal, neurodegenerative, Tay-Sachs disorder?
a. Defect in or absence of the enzyme (
-N-acetylhexosaminidase) which facilitates
break down of gangliosides
b. Defect in synthesis of gangliosides
c. Defect in the synthesis of dipalmitoyl-phosphatidyl choline
d. Defect in an enzyme (prenyl transferase) which is necessary for the synthesis of
2.How are sugars usually activated in the synthesis of phospholipid head groups? They are:
3.Which is NOT a use of phosphatidic acid in cells?
a. Phosphatidic acid is activated to produce squalene during cholesterol biosynthesis.
b. Phosphatidic acid is activated by CTP during phospholipid synthesis.
c. Phosphatidic acid is dephosphorylated and receives an activated fatty acid to form
d. Phosphatidic acid is dephosphorylated to diacylglycerol and receives an activated
alcohol head group to form a phospholipids
e. Phosphatidic acid is an important precursor in the synthesis of uric acid
4.Fatty acids are activated before addition to glycerol or dihydroxyacetone phosphate
a. Through a Thiol-ester linkage to CoA
b. Through ester linkage with UDP
c. Through phosphorylation
d. All the above are used
5.Which reaction below is the regulated step in cholesterol synthesis?
a. acetoacetyl-CoA + acetyl CoA + H
O > HMG-CoA + CoA
b. HMG-CoA + 2H
+ 2NADPH > Mevalonate + 2NADP
c. HMG-CoA + acetyl CoA
> Squalene + CoA
d. 2 acetyl-CoA > acetoacetyl-CoA
6.Please put these synthetic reactions in order:
a. 1, II, 1V, V, III
b. 1V, 1, II, V, III
c. 1, 1V, III, II, V
d. 1V, V, II, I, III
e. 1, II, III, 1V, V
Formation of Squalene
Formation of Farnesyl pyrophosphate
III. Cyclization to Lanosterol
Formation of 3-Isopentyl pyrophosphate
Formation of Geranyl pyrophosphate