Download C383 Study Guide for the Final Exam Spring 2016 Basic Information

C383 Study Guide for the Final Exam
Spring 2016
Basic Information
 Final Exam: Friday, May 6, 10:15-12:15 PM in Rawles Hall 100
 Arrive early for assigned seats
 Bring your student ID. If you do not, you will need to bring it Monday!!!
 You may use a NON-PROGRAMMABLE calculator.
 All papers, books, phones, and electronic devices must be in a sealed bag under your seat.
Exam Content: The exam will have two major parts.
A. 50 points covering chapters 27-31. This exam will look much like what you have
seen in the other midterm exams, including multiple choice, short answer, and problems.
Major topics include: hormone sensitive lipase, steps of beta-oxidation, ketone bodies, contrast
fatty acid degradation and synthesis, regulation of acetyl CoA carboxylase, stages of cholesterol
synthesis, regulation of cholesterol synthesis, ammonia fixing pathway, glutamine synthetase,
transamination mechanism, essential/nonessential amino acids, carbon sources of nonessential
amino acids, role of THF, ketogenic/glucogenic amino acids, entry of carbon backbone into
metabolism for the amino acids on the slides, motifs in catabolism of branched amino acids,
nitrogen cycle from muscle, urea cycle input and outcome and ATP expenditures, role of main
amino acids in nitrogen metabolism
B. 100 point cumulative exam. This exam will cover major themes and integrated
concepts for the course. It will be about 1/3 multiple choice, 1/3 short answer, and 1/3 problems
taken from the list below. These questions will also serve as a good review for the major topics
of the course. You are encouraged to use them as a study guide. You may work with others in
the class to work through these problems. The instructor and AI will not assist you or provide
answers.
Questions:
1. S-acetonyl-CoA (shwn below) has by synthesized and tested as an inhibitor of citrate
synthase.
A. Write the reaction catalyzed by citrate synthase.
B. Why is the name of this enzyme not “citrate synthetase”?
C. The Lineweaver burke plot of this enzyme with and without the inhibitor is show belos. What
type of inhibitor is it? Explain.
D. Based on these data, how would you expect this inhibitor to effect pyruvate carboxylase?
How would this effect gluconeogenesis?
2. Given a name, draw chemical structures of: ATP, all amino acids, all glycolysis intermediates,
acetyl CoA, all citric acid cycle intermediates
3. Explain the logic of these pathway regulations:
A. Phosphofructokinase, not hexokinase, is the main regulation site of glycolysis.
B. SuccinylCoA inhibits the entry of acetyl CoA into the citric acid cycle.
C. NADH inhibits pyruvate dehydrogenase.
D. Citrate inhibits the citric acid cycle and activates acetyl-CoA carboxylase.
E. Insulin leads to activation of glycogen synthase.
4. Describe each cycle/transport system (compounds, compartments, tissues) and explain its
purpose:
A. citrate transport system
B. Cori cycle
C. glucose/alanine cycle
5. For each of these cofactors, explain its chemical function and give an example of a type of
enzyme that would use it: TPP, PLP, biotin, FAD, NADPH
6. Drawing figures. In the spaces below, draw an appropriately shaped figure, including
necessary axis labels.
A. A titration curve for lysine, with a side chain pKa of 10.5.
B. A DNA melting curve for a poly(AT) sequence and a poly(GC) sequence (indicate which is
poly(AT) and which is poly(GC))
C. A plot of initial velocity versus substrate concentration for a Michaelis-Menton enzyme.
D. The same plot as (B), but the enzyme is treated with a competitive inhibitor
E. a pH profile for an enzyme with two key ionized residues: a cysteine with pKa 4.2 and a
Histidine with pKa 8.2
F. Saturation curve for myoglobin and hemoglobin (indicate which is which)
7. Draw the structures of the following molecules in their major ionization state in a buffer at pH 3 and a
buffer of pH 7. (See a table for necessary pKa values.)
A. cysteine
B. oxaloacetate
C. D-mannose
D. the tripeptide PKV
8. Integrated metabolism
A. A molecule of glucose that you eat can eventually be transformed into part of a fatty acid that
you store. Circle the pathways/cycles below that are part of this overall flow of carbon atoms.
Cross out any that are not.
Gluconeogenesis, beta-oxidation, citric acid cycle, glycolysis, urea cycle, fatty acid synthesis
B. Trace the metabolic path of this glucose molecule through the enzymes it encounters along
the way to being made into fat. Write all the enzymes in the list below into the proper places in
the figure below. If the enzyme is not used, write its name in the “not used” box. If it is used,
write the enzyme in the order that the carbon atoms from glucose encounter the enzymes.
Pyruvate dehydrogenase, fumarase, aldolase, lactate dehydrogenase, pyruvate kinase, acetyl CoA
carboxylase, fatty acid synthase, hexokinase, carnitine acyltransferase, ATP synthase
B. What is the minimum number of glucose molecules that would be necessary to be the carbon source
for synthesis of a 16-carbon fatty acid through this pathway?
C. How many net glucose can be made from one molecule of a 16-carbon fatty acid?
9. Integrated metabolism
A. A molecule of glutamate that you eat can eventually be transformed into part of a glucose
molecule that you store in your liver. Circle the pathways/cycles below that are part of this
overall transformation. Cross out any that are not.
Gluconeogenesis, pentose phosphate pathway, glycogen synthesis, glycolysis, citric acid cycle
B. Trace the metabolic path of this glutamate molecule through the intermediates it becomes on
the way to being glucose. Draw the structure of glutamate and -D-glucose in the boxes.
Indicate the order of transformation by writing “1”, “2”, etc next to each appropriate structure.
Cross out the one molecule not involved in this pathway.
C. The nitrogen atom of glutamate must be removed by oxidative deamination, and is
incorporated into a molecule that is excreted. Draw the structure of this molecule.