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CASE FILES: BIOCHEMISTRY
= 0 dihydroxyacetone-P
1 Hexokinase
6
2 Glucose-6-P isomerase
7
3 6-Phosphofructokinase
8
4 Fructose 1,6-bisphosphate aldolase
9
5 Triosephosphate isomerase
10
11
3-Phosphoglyceraldehyde dehydrogenase
Phosphoglycerate kinase
Phosphoglyceromutase
Enolase
Pyruvate kinase
Lactate dehydrogenase
Figure 27-4. Glycolytic pathway under conditions of insufficient oxygen.
C O M P R E H E N SIO N Q U E ST IO N S
A middle-aged man, after an episode of retrosternal chest pressure with radi-
ation to the neck and associated nausea and diaphoresis while at rest, was
given a diagnosis of unstable angina and possibly myocardial infarction.
Subsequent laboratory findings of increased serum levels of troponin I and
cardiac enzymes were consistent with the diagnosis.
[27.1] If the patient described above did indeed have angina, which of the fol-
lowing change(s) in metabolism in the affected area would occur?
A. Increased oxidative phosphorylation
B. Increased rate of fatty acid oxidation
C. Increased conversion of pyruvate to acetyl-CoA
D. Increased formation of lactate
E. Increased use of ketone bodies
[27.2] In the case described above an ischemic episode very likely occurred.
What changes in glucose metabolism would be observed?
A. The overall rate of glucose utilization would decrease.
B. Pyruvate kinase is allosterically inhibited.
C. The rate of ATP production in the cytosol increases.
D. NADH is reoxidized to NAD+ via the glycerol 3-phosphate shuttle.
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