19. Fructose metabolism – absorption, organ specificity of degradation and association with other metabolic pathways. Defects in fructose metabolism – essential fructosuria and fructose intolerance. Nonalcoholic fatty liver disease.

Describe the process of fructose absorption in the small intestine. How does it differ from glucose absorption?

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What are the main organs involved in fructose metabolism?

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What are the key enzymes involved in fructose metabolism in the liver? Describe the reactions they catalyze.

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Why does fructose metabolism proceed more rapidly than glucose metabolism?

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Explain the differences between essential fructosuria and hereditary fructose intolerance (HFI), including their causes, symptoms, and biochemical consequences.

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Why does the accumulation of fructose 1-phosphate in HFI lead to hypoglycemia?

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What are the long-term consequences of untreated HFI? How is HFI diagnosed and managed?

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Can fructose be converted into glucose in the body? If so, explain how.

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Describe the role of aldose reductase in the metabolism of fructose and glucose. What are the clinical implications of its activity under hyperglycemic conditions?

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Describe how mannose is converted into fructose 6-phosphate.

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Discuss the importance of converting glucose into fructose via sorbitol, particularly for sperm cells.

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