A marker of Golgi apparatus is
**Core Concept**
The Golgi apparatus is a complex organelle responsible for protein modification, sorting, and packaging in eukaryotic cells. It plays a crucial role in protein synthesis and secretion. The Golgi apparatus is composed of flattened sacs called cisternae, stacked on top of each other, and is involved in various cellular processes, including glycosylation, phosphorylation, and lipid modification.
**Why the Correct Answer is Right**
A marker of the Golgi apparatus is an enzyme or protein that is specifically localized to this organelle and is used as a diagnostic tool to identify Golgi apparatus activity. One such marker is **Nucleotide Sugar Transporter 1 (NST1)**, which is involved in the transport of nucleotide sugars across the Golgi membrane. Another marker is **Protein Disulfide Isomerase (PDI)**, which is a enzyme that catalyzes the formation and rearrangement of disulfide bonds in proteins within the Golgi apparatus.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a Golgi apparatus marker.
**Option B:** This option is incorrect because it is not related to the Golgi apparatus.
**Option C:** This option is incorrect because it is not a recognized marker of the Golgi apparatus.
**Clinical Pearl / High-Yield Fact**
Golgi apparatus dysfunction can lead to various cellular disorders, including inherited metabolic diseases, such as GM1 gangliosidosis, which is caused by a deficiency of the enzyme **beta-galactosidase**, which is involved in the degradation of gangliosides within the Golgi apparatus.
**Correct Answer:** C.