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Chemistry 256
Sample mid-quarter exam 1 (winter 2015)
1. Which one of the following processes is not stimulated by insulin?
a. Glucose uptake in muscle
b. Dephosphorylation of glycogen synthase in muscle
c. Glycolysis in the liver
d. Dephosphorylation of glycogen synthase in liver
e. All of the processes listed are stimulated by insulin
2. a Which enzyme would you use to remove a phosphate group from the enzyme
glycogen phosphorylase a to form glycogen phosphorylase b
Phosphorylase kinase
Protein kinase
Phosphoprotein phosphatase
Glucose Phosphorylase
b. Would this event activate or deactivate or have no effect on the enzyme glycogen
phosphorylase?
c. The above event is considered a (circle all that apply):
Covalent modification of an enzyme
Allosteric modification of an enzyme
Genetic modification of the enzyme
Example of an enzymatic cascade
3. Cyclic AMP is considered a:
Hormone
Steroid
Second messenger
A receptor
Enzyme
4. Chylomicrons contain which molecules:
Acety-CoA
Cholesterol esters
Glycogen
Isoprene pyrophosphate
Triacylglyderides
5. Circle which below would give a membrane a higher melting point
a.
b.
c.
d.
Incorporation of more cholesterol
Longer Chain lengths of the fatty acid components
Less unsaturation of the fatty acid components
Cross linking of fatty acid components
6. For integral proteins associated with cell membranes what type of amino acid
residues would be found exclusively within the membrane.
7. While fatty acids are most often formed by the condensation of __-carbon units,
isoprenoids are assembled from __-carbon units.
a. 5, 3
b. 4, 2
c. 2, 3
d. 2, 5
e. 3, 4
8. Which enzyme catalyzes the key regulatory step of cholesterol synthesis?
a. b-ketothiolase
b. HMG-CoA synthase
c. HMG-CoA reductase
d. mevalonate kinase
e. squalene monooxygenase
9. In Gluconeogenesis the steps that are simply the reverse of Glycolysis
a)
b)
c)
d)
e)
Have a G that is near 0.
Have a G that is a large + value
Have a G that is a large – value
Are considered the rate control steps
All step are the reverse of glycolysis
10. If the liver is analyzed, and the ratio of phosphorylase a (active form) to
phosphorylase b is found what processes would probably be occurring?
Gluconeogenesis
Glycolysis
Glycogen breakdown
Glycogen build up (synthesis)
11. Which synthetic pathway(s) does the class of drugs called ‘statins’ effect
Gluconeogenesis
Glycolysis,
Glycogen breakdown
Glycogen build up
Cholesterol synthesis
Fatty acid synthesis.
12. Which pathways does Acetyl CoA participate in (as a reagent or product)?
Gluconeogenesis
Glycolysis
Glycogen breakdown
Glycogen build up
Cholesterol synthesis
Beta oxidation of fats
Citric acid cycle
Fatty Acid synthesis
13. Draw the general structure/example of each class of molecules listed below
Triacyl glyceride
Phosphoglycerides
Carbohydrate
Bile Salts
Steroid
Terpenes
Spingolipids
14. Which molecules drawn above would you attribute the property of amphipathic.
15. Which processes below consume more energy than they produce? (consume ATP,
NADPH etc )
Gluconeogenesis
Glycolysis
Citric acid cycle
Cholesterol synthesis
Pentose phosphate pathway
Fatty acid oxidation
Fatty acid biosynthesis
16. What make the isopentyl pyrophosphate molecule so reactive?
17. Describe the role and purpose of Prostaglandins
18. Which molecule has a higher energy density by weight—Glycogen or
Triacylglyerides.
19. In the synthesis of glycogen, pyrophosphate (PPi) is hydrolyzed by water to form 2
phosphate groups. What is the purpose of this step? Is what other synthesis does this
occur?
20 B What enzyme was used for this step
a.
b.
c.
d.
e.
Phophofructokinase
Fructose bisphosphatase
AcetylCoA-Carboxylase
Glucoreductase
Protein mutase
21. A For the reaction below, what process is this from:
a.
b.
c.
d.
e.
f.
Glycolysis
Cholesterol synthesis
Fatty acid biosynthesis
B-oxidation
Gluconeogenesis
Pentose phosphate pathway
O
SCoA
H2O
OH
O
SCoA
22B What enzyme was used for this step?
a.
b.
c.
d.
e.
Phophofructokinase
Lipolphosphatase
AcetylCoA-Carboxylase
Hydroxyl acetyl dehydrogenase
Enoyl-coA hydratase
23 For the reaction below, draw in the arrow pushing mechanism of the next step
where 2,3 oxidosqualene is converted to the basic cholesterol structure
mechanism
Using the chart below answer 29-32
24. Which direction is glycolysis (going down or up)
25. Which direction creates energy (rather than consumes)?
26. Which step is the allosteric inhibitor F2,6P important.
27, Which enzyme does F2,6P inhibit?
28, Increased Glucagon secretion will promote which direction of this process
(up/down)
29. A For the reaction below, what process is this from:
-2
O3PO
OPO32-
-2
O3PO
O
HO
O
H
H
HO
OH
30. Show the product of the reaction below:
O
(CH2)8CH3
O
OH
OPO32-
OH
H
Glycolysis
Glycogen synthesis
Fatty acid biosynthiss
B-oxidation
Gluconeogenesis
Pentose phosphate pathway
O
+
R
H
H
OH
H
a.
b.
c.
d.
e.
f.
OH
acyltransferase
SCoA
OH