Which of the following is not a product of complete hydrolysis of Sphingomyelin?
**Core Concept**
Sphingomyelin is a type of sphingolipid that is abundant in cell membranes, particularly in the myelin sheath of nerve cells. Complete hydrolysis of sphingomyelin involves the breakdown of its glycerophosphodiester bond, releasing ceramide and phosphocholine.
**Why the Correct Answer is Right**
Complete hydrolysis of sphingomyelin produces ceramide, phosphocholine, and fatty acid. This process is catalyzed by the enzyme sphingomyelinase, which is involved in the metabolism of sphingomyelin. The resulting ceramide acts as a signaling molecule, influencing various cellular processes such as apoptosis and cell growth. Phosphocholine is further metabolized to form choline, which can be used for the synthesis of phospholipids and other molecules.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because sphingosine is indeed a product of sphingomyelin hydrolysis, but only partial hydrolysis produces sphingosine and phosphocholine.
**Option B:** This option is incorrect because phosphocholine is a correct product of sphingomyelin hydrolysis.
**Option C:** This option is incorrect because ceramide is indeed a product of sphingomyelin hydrolysis.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that sphingomyelinase deficiency is associated with Niemann-Pick disease, a group of genetic disorders characterized by the accumulation of sphingomyelin in cells, leading to neurodegeneration and other systemic complications.
**Correct Answer: A. Sphingosine**