From where do cells acquire necessary free energy?
Can cells use heat as a free energy source? Why or why not?
Why do relatively small changes in ΔG’º correspond to large changes in K’eq?
Explain the difference between: ΔG, ΔGp and ΔG’º
Why are adenylylation reactions thermodynamically favorable?
List the different electron donating compounds that provide energy for the work done by biological organisms?
What coenzymes carry electrons in the cell, and in what types of reactions do they play a role?
Briefly define oxidation and reduction.
Can an oxidation occur without a simultaneous reduction? Why or why not?
Why is NAD considered a substrate and FAD considered a cofactor?
The thermodynamics of an oxidation/reduction reaction is the same as that found for any other chemical reaction. True or False?
Many chemical species take part in electrode reactions. Briefly describe the application of the Nernst equation. What can its calculation tell you?
With respect to thermodynamics, why can biosynthetic pathways not be simply considered the reverse of corresponding catabolic pathways?
Compare the net equations of glycolysis and gluconeogenesis and explain why the synthesis of glucose is so costly.
Why is the biosynthesis of glucose so important in mammals?
List the following:
a. Most common precursors for glucose biosynthesis
b.Organs which use glucose as their primary energy source
c. Organs or tissues where gluconeogenesis takes place
Explain in detail how both glycolysis and gluconeogenesis can be irreversible cellular processes.
What drives the conversion of fructose 1, 6- bisphosphate to fructose 6 -phosphate?
Describe the role of malate transport in gluconeogenesis.
How does fatty acid oxidation contribute to gluconeogenesis? Under what conditions do amino acids get converted to glucose?
What are the effects of G6P, F1,6-BP, F2,6-BP on glycolysis and gluconeogenesis?
What are the effects of cAMP, AMP, ATP, citrate and acetyl-CoA on glycolysis and gluconeogenesis?
How many ATP equivalents are required to synthesize a glucose from two pyruvate in order to bypass the irreversible steps in glycolysis?
Why are sugar nucleotides suitable for biosynthetic reactions?
How does F2,6-BP control the conversion of F6P to F1,6-BP or the reverse?
In the final stages of gluconeogenesis, glucose-6-phosphatase converts glucose-6-phosphate to free glucose and inorganic phosphate. Where does this occur?
Read the article below. This study addresses the synthesis of a trisaccharide that humans do not metabolize. Why are studies such as this and others which examine bacterial systems for enzymatic activity on carbohydrates ultimately beneficial to addressing human health concerns? Perrin V, Fenet B, Prally J, Lecroix F, and Ta CD. (2000) Carbohydrate Research, 325 (3): 202-210.
Hepatocytes are an important model for in vitro study of metabolism. Read the article below and describe how the supplementation of cell culture media with amino acids and hormones affected the activity of hepatocytes and the occurrence of futile cycles. Chan C, Berthiaume F, Lee K, and Yarmush M. (2003) Metabolic Engineering, 5 (1): 1-15.