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See below for study guide questions for the final exam. 31P MRS Experience What
is the proposed function of the creatine kinase/phosphate shuttle in contracting
skeletal muscle? What
is the source of the increasing concentration of Pi during intense exercise? Glycogenolysis
and Glycolysis Is
phosphorylase the only enzyme needed during glycogenolysis?
If not, why? Explain
the multifaceted biochemical regulation of glycogenolysis. Why
is the regulation of glycogenolysis important for influencing the potential flux
through glycolysis? Why
does intramuscular free glucose increase during glycogenolysis? Why
is lactate production important for the acute ability to continue glycolysis
during intense exercise? Acidosis What
are the sources of protons during muscle contraction? Is
it correct to interpret lactate production as the cause of muscle acidosis?
Why? Why
does ATP hydrolysis release a proton? How
would you explain the biochemistry of metabolic acidosis during exercise? What
is the strong ion difference (from Stewart Physico-chemical approach), and how
is it used to argue for the development of metabolic acidosis? What
is a dissociation constant, and how is it different to an association constant? Mitochondrial
Respiration Compared
to glycolysis, explain where the added sources of ATP come from during oxidative
phosphorylation from glucose. At
what stages of metabolism is CO2 produced for both fats and
carbohydrates? Why
are only two molecules of ATP generated for each FADH + H+ during the
Electron Transport Chain? What
is special about the cytosolic and mitochondrial concentrations of NAD and NADH
? For example, if they are
different, why are they different? Assuming
all the molecules of the TCA Cycle and Electron Transport Chain are present,
what substrates are needed in the mitochondria for continuation of
the electron transport chain and ATP production? Why
is electron flow along the Electron Transport Chain unidirectional? What
does the phrase "uncoupling of oxidative phosphorylation" mean? Explain
the process of FFA mobilization and fatty acid oxidation during low intensity
exercise? Why
is there an increased in carbohydrate catabolism during increasing exercise
intensities? Order
the following from lowest to highest reduction potential.
1/2 O2 ; NAD+
; cytochrome C ; pyruvate
Why did you order these molecules this way? What
are the similarities between the hormonal activation of glycogenolysis and
lipolysis? What
are the enzyme(s) responsible for FFA mobilization? Compare
where CO2 is produced during FFA catabolism and carbohydrate
catabolism. For a given amount of
ATP production, catabolism of which substrate yields more CO2?
Why? It
is generally recognized the more ATP per liter of oxygen is produced from CHO
than FFA. Evaluate the two pathways
of catabolism and try to explain why this is so (a tough one !!!). There
are several potential rate-limiting reactions to FFA catabolism.
Given a diagram of FFA catabolism, what and where are they, and explain
why they may be rate limiting. What
is the role of carnitine during FFA catabolism, and during exercise of
increasing intensity? Post-exercise
Protein Synthesis Explain
the differences between transcription and translation. What
are examples of regulators of DNA transcription? What is the function of tRNA during protein synthesis? Does
transcription and translation always result in active/functional proteins?
What often needs to happen for a protein to be functional? How
does exercise influence protein degradation and synthesis? Does
amino acid availability alter post-exercise protein synthesis?
Are all amino acids and proteins equal in
supporting muscle protein synthesis? Explain
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