C483 Final Exam Study Guide

The final will be held in CH 001 at 8-11AM on Friday, July 29. There will be no excused absences for the final.

There are two parts to the final exam.

A. 100 points covering chapters 17-19. This exam will look much like what you have seen in the other midterm exams.

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 directly 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. Pratt question 13.20

2. Pratt question 13.55. Explain how you came to your answer.

3. Pratt question 14.14

4. Pratt question 14.40

5. Given a name, draw chemical structures of: ATP, all amino acids, all glycolysis intermediates, acetyl CoA, all citric acid cycle intermediates

6. 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.

7. Describe each cycle/transport system (compounds, compartments, tissues) and explain its purpose:

A. malate/aspartate shuttle

B. citrate transport system

C. Cori cycle

D. glucose/alanine cycle

8. 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

9. 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

C. 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?

D. How many net glucose can be made from one molecule of a 16-carbon fatty acid?

10. 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 a-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.

11. 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)