Fructose intolerance is due to deficiency of
**Fructose Intolerance**
**Core Concept**
Fructose intolerance is a condition where the body is unable to properly metabolize fructose, a simple sugar found in many fruits, vegetables, and processed foods. This occurs due to a deficiency in the enzyme responsible for breaking down fructose in the liver.
**Why the Correct Answer is Right**
The correct enzyme involved in the breakdown of fructose is Aldolase B (also known as fructose-1,6-bisphosphate aldolase). This enzyme catalyzes the conversion of fructose-1-phosphate to glyceraldehyde and dihydroxyacetone phosphate in the liver. A deficiency in Aldolase B leads to the accumulation of fructose-1-phosphate, causing symptoms of fructose intolerance.
**Why Each Wrong Option is Incorrect**
* **Option A:** Glucose-6-phosphatase is the enzyme involved in glucose metabolism, specifically in the final step of gluconeogenesis and glycogenolysis in the liver. Its deficiency leads to von Gierke's disease, a disorder of glycogen storage.
* **Option B:** Fructokinase is an enzyme involved in the initial step of fructose metabolism, converting fructose to fructose-1-phosphate. However, a deficiency in fructokinase leads to a different condition, essential fructosuria, which is a benign condition characterized by the presence of fructose in the urine.
* **Option C:** This option is blank. I will wait for your input on what option to fill.
**Clinical Pearl / High-Yield Fact**
It's essential to note that fructose intolerance is a rare condition, and most cases are due to a deficiency in Aldolase B. A high-fructose diet can exacerbate symptoms of fructose intolerance, and patients may benefit from a low-fructose diet to manage their symptoms.
**Correct Answer:** D. Aldolase B.