Microsoft word - fall_2011_ex_3.doc

Biological Sciences 4087
11/17/10
Total: 100 points There are 5 pages and 12 question on this exam. Question 12 is
an essay question.
1.(14pts) Fill in the blanks.
A. Metformin (used to treat type 2 diabetes mellitus) inhibits the synthesis of
phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. These enzymes are part
of the pathway (name the pathway):
__________________________________________________ B. The insulin receptor directly phosphorylates the protein (do not name the receptor
itself):
__________________________________________________ C. Nitric oxide (NO) is made from the amino acid _______________________________
D. An SH2 domain in a protein binds to _______________________________________
E. The enzyme that hydrolyzes and inactivates cGMP is
__________________________________________________ F. The ErbB protein is a truncated form of the protein
__________________________________________________
G. In the insulin receptor signaling pathway, Ras is directly activated by the protein
__________________________________________________ 2.(2pts) Name 2 noncarbohydrate precursors that can be used to synthesize glucose in
the liver. (Name 2 different precursors.)

3.(2pts) Name a pathway that produces NADPH in animals.
__________________________________________________ 4.(14pts) Write out the pathway for glycolysis from glucose to pyruvate. Indicate the
products of glycolysis and where they are formed. Label the steps catalyzed by
regulatory enzymes and name those enzymes.


5.(4pts) What is the function of each of the following in glycogen metabolism? Be
specific.
A. UDP-glucose pyrophosphorylase-
B. glycogenin-
6.(9pts) Identify (Write out the complete names):
A. ______________________________________


B. ______________________________________

C. ______________________________________

7.(9pts) A. Write out the complete pathway for the stimulation of glycogen degradation
by the hormone glucagon in liver. Begin with the hormone’s receptor.


B. Name an allosteric effector for the regulatory enzyme for glycogen degradation in
liver and describe its effect on the enzyme.
8.(9pts) A. Write out the reaction catalyzed by the pyruvate dehydrogenase complex.
B. Name the 3 cofactors of the pyruvate dehydrogenase complex. Write out the complete
names.

9.(12pts) Fill in the blanks regarding fatty acid metabolism.
A. The protein surrounding the lipid droplet in adipocytes is ______________________.
B. Glycerol enters glycolysis/gluconeogenesis by being converted to the glycolytic
intermediate (write out the complete name)

C. Fatty acids are transported into mitochondria attached to
D. Each round of fatty acid β oxidation produces _______________________________,
________________________________, and _______________________________
E. Coenzyme B12 is needed to convert propionyl CoA to the citric acid cycle intermediate
F. An example of a ketone body is ____________________________________.

10.(7pts) Write out the pathway for mitochondrial electron transport from NADH to O2.
Write out the complete name of the complexes (not just the numbers).
11.(10pts) Fill in the blanks (write out the complete names):
A. In the urea cycle, argininosuccinate is cleaved to ____________________________
and _________________________________.
B. The prosthetic group of aminotransferases is _________________________________.
C. The amino acid ____________________________________ is degraded to fumarate.
D. One of the nitrogens of urea is supplied by the amino acid ______________________.
E. A deficiency in phenylalanine hydroxylase results in the genetic disease
__________________________________________ 12.(8pts) HIF-1 is produced under low oxygen conditions in tissue. Discuss the effects
of HIF-1 on metabolic pathways in the hypoxic tissue.

Source: http://www.pmoroney.biology.lsu.edu/Exams/Fall2011ex3.pdf