Figlu is an intermediate product of the following amino acid:
**Core Concept**
Histidine is an essential amino acid that undergoes catabolism through the histidine degradation pathway, resulting in the formation of formiminoglutamate (Figlu), which is an intermediate product of this process. The histidine degradation pathway involves a series of enzyme-catalyzed reactions that ultimately lead to the breakdown of histidine into formiminoglutamate and other products.
**Why the Correct Answer is Right**
The histidine degradation pathway begins with the removal of the imidazole ring from histidine, resulting in the formation of formiminoglutamate (Figlu). This reaction is catalyzed by the enzyme histidase. Formiminoglutamate is then converted into glutamate through a series of reactions involving the enzyme formiminotransferase. The histidine degradation pathway is an important mechanism for the breakdown of histidine, a conditionally essential amino acid that must be obtained from the diet.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct amino acid that is broken down to form Figlu.
**Option B:** This option is incorrect because it is not directly related to the histidine degradation pathway or the formation of Figlu.
**Option C:** This option is incorrect because it is not a known intermediate product of the histidine degradation pathway.
**Clinical Pearl / High-Yield Fact**
The histidine degradation pathway is an important mechanism for the breakdown of histidine, a conditionally essential amino acid that must be obtained from the diet. Deficiencies in the enzymes involved in this pathway, such as histidase deficiency, can lead to elevated levels of Figlu in the urine.
**Correct Answer:** C. Histidine.