CLINICAL CASES
215
C O M P R E H E N SIO N Q U E ST IO N S
A young man with normocytic anemia, jaundice, and splenomegaly was diag-
nosed as having RBC pyruvate kinase deficiency after a peripheral blood
smear showed spiculated cells.
[23.1] Since in this patient pyruvate kinase is abnormal not only is less pyruvate
made but intermediates above pyruvate in the glycolytic pathway build up
slowing the pathway. Which of the following products may not be made
in the appropriate amounts in the RBC because of the deficiency of
pyruvate?
A. Glucose
B. Oxaloacetate
C. acetyl-CoA
D. Lactate
[23.2] In the RBCs of the patient described above, which of the following
would be expected?
A. ADP to ATP ratios would be elevated above normal.
B. NADP+ would increase relative to NADPH.
C. Ribulose 5-phosphate levels would decrease.
D. NADH to NAD+ ratios would decrease.
E. Methemoglobin levels would increase.
[23.3] The glycolytic pathway is a multistep process by which glucose is broken
down to a three-carbon metabolite. Some of the steps are listed below:
1.
Conversion of 3-phosphoglycerate to 2-phosphoglycerate
2.
Conversion of phosphoenolpyruvate to pyruvate
3.
Conversion of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate
4.
Conversion of glucose to glucose 6-phosphate
5.
Conversion of fructose 6-phosphate to fructose 1,6-bisphosphate
Which of the following is the correct order of these conversions?
A. 4 ^ 5 ^ 1 ^ 2 ^ 3
B. 4 ^ 3 ^ 1 ^ 2 ^ 5
C. 4 ^ 5 ^ 3 ^ 1 ^ 2
D. 4 ^ 1 ^ 3 ^ 5 ^ 2
E. 4 ^ 5 ^ 3 ^ 2 ^ 1
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