Download Discussion Questions for Week 5: HWA Pages 167-177

Discussion Questions for Week 5: HWA Pages 167-177
1. Define and briefly describe the major sets of reactions in aerobic catabolism.
2. How are oxidative phrosphorylation and substrate level phosphoylation different?
3. HWA states that, in a very narrow sense, glycolysis and the Kreb’s cycle can proceed
without O2. Why, then, is O2 necessary for aerobic catabolism?
4. For each electron pair that originally comes from NADH and passes completely through
the electron transport system, how many ATPs are produced?
5. The production of lactic acid in anaerobic conditions can be both a benefit and a
disadvantage. Explain why.
6. Phosphagens can be used to produce ATP as well. How does this mechanism work?
7. It is common belief that lactic acid causes muscle fatigue. Based on your reading, do you
believe this to be true?
8. What other factors are mentioned that are believed to cause muscle fatigue?
9. In glycolysis, how many CO2 molecules are formed for each glucose molecule oxidized?
10. The ETC pumps protons from the matrix to the core of the mitochondria. The protons
become concentrated in the intermembrane space and tend to diffuse back into the matrix.
What two types of proteins discussed may play a role in this back-diffusion?
11. What is the P/O ratio? When does a cell ever reach the theoretical maximum P/O ratio?
12. Compare the pros and cons of operating in a steady state versus a non-steady state.
13. Do a little research to find factors that can affect a person’s metabolism, then compare
this to your reading. Say an individual wants to lose weight and is wondering if the best
exercise is swimming or working out in gym. Based on your new knowledge, what would
you suggest to this individual?
14. Angie, a 15 yr old female, was admitted to the hospital because of recurrent episodes of
pallor, jaundice, and an ulcer on her left leg. Diagnosis of hemolytic anemia had been made
at the age of 3 months, and she had been transfused several times since the diagnosis.
Physical examination showed jaundice, skeletal growth retardation, and enlargement of the
spleen. An analysis of blood showed low Hb content, low RBC count, and elevated
reticulocyte count. Morphologic analysis revealed a mixed population of RBCs containing
some irregularly contracted cells with irregular surface projections. The life span of the
RBCs was found to be severely shortened. Both total and indirect serum bilirubin levels were
markedly elevated. Fecal urobilinogen excretion was increased. Biochemical analysis of
RBC metabolites showed elevated levels of 2,3 bisphosphoglycerate (2,3 BPG) and reduced
levels of ATP. A splenectomy was performed; the spleen showed congestion and the
presence of hemosiderin granules. Following splenectomy, there was improvement in both
the clinical and hematologic symptoms. An increase in hemoglobin concentration as well as
in the number of RBCs and reticulocytes was observed. The biochemical composition of the
RBCs did not change after splenectomy.
Please answer the following:
What is the problem with this patient?
What is the source of ATP in red blood cells?
What are Reticulocytes?
Why did her RBCs change shape?
What is bilirubin?
14. How many ATP molecules are formed from one mole of glucose in glycolysis?
15. In Kreb’s cycle, how many NADH molecules are formed from one glucose molecule?
16. In Kreb’s cycle, how many ATPs are formed from one mole of glucose by substrate level
phosphorylation?
17. What acid is formed from the combination of acetyl CoA and oxaloacetic acid?
18. For each electron pair that originally comes from NADH and passes completely through
the electron transport system, how many ATPs are produced?
19. What is the name of the integral protein in the inner mitochondrial membrane
responsible for conversion of ADP to ATP?
20. When supplies of intracellular O2 become low, what is pyruvate converted to such that
glycolysis can proceed?
21. From 10 moles of glucose, how many moles of ATP would be formed in glycolysis
assuming O2 is plentiful in the cell?
22. From the intracellular oxidation of one mole of glucose, how many moles of CO2 would
be formed in glycolysis? In Kreb’s Cycle?
23. When one mole of glucose (180 g) is burned in a bomb calorimeter, 2816 kJ of heat is
released. When one mole of glucose is completely oxidized in cellular metabolism, how
much heat is released?