188
CASE FILES: BIOCHEMISTRY
[20.4]
A. Hexokinase is found in most tissues, and because of the very low
Km for glucose, it is designed to work maximally to provide ATP for
tissue even at low levels of glucose. Hexokinase is inhibited by glucose
6-phosphate and is most active with low levels of glucose 6-phosphate.
Glucokinase found in the liver has a high Km for glucose and is very
active after a meal. The glucose in the soda would likely be used for
ATP production.
B IO C H E M IS T R Y PE A R L S
The etiology of the syndrome is not clear, although recent reports
have linked some cases of AFLP with a fetal inborn error in fatty
acid metabolism.
Following a meal, glycogen concentrations within the liver rise rap-
idly to high levels; this can be up to 10 percent of the wet weight
of the liver.
Liver insufficiency may be associated with hypoglycemia.
REFERENCES
Castro M, Fassett MJ, Telfer RB, et al. Reversible péripartum liver failure: A new
perspective on the diagnosis, treatment, and cause of acute fatty liver of preg-
nancy, based on 28 consecutive cases. Am J Obstet Gynecol 1999;181:389-95.
Rakheja D, Bennett MJ, Rogers BB. Long-chain L-3-hydroxy acyl-coenzyme A
dehydrogenase deficiency: A molecular and biochemical review. Lab Invest
2002;82:815-24.
Roe CR, Ding J. Mitochondrial fatty acid oxidation disorders. In: Scriver CR,
Beaudet AL, Sly WS, et al., eds. The Metabolic and Molecular Basis of Inherited
Disease, 8th ed. New York: McGraw-Hill, 2001:2297-2326.
Saudubray J-M, Charpentier C. Clinical phenotypes: diagnosis/algorithms. In:
Scriver CR, Beaudet AL, Sly WS, et al., eds. The Metabolic and Molecular Basis
of Inherited Disease, 8th ed. New York: McGraw-Hill, 2001:1327-1403.
Yang Z, Yamada J, Zhao Y, et al. Prospective screening for pediatric mitochondrial
trifunctional protein defects in pregnancies complicated by liver disease. JAMA
2002;288:2163-66.
previous page 202 Case Files   Biochemistry read online next page 204 Case Files   Biochemistry read online Home Toggle text on/off