The trans face of the Golgi apparatus is generally closer than the cis face (of the Golgi apparatus) to which of the following eukaryotic structures?
A. the inner nuclear membrane
B. the smooth endoplasmic reticulum
C. the plasma membrane
D. the rough endoplasmic reticulum
E. the nuclear pores
The correct answer and explanation is:
The correct answer is C. the plasma membrane.
The Golgi apparatus is a crucial organelle in eukaryotic cells responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles. The Golgi consists of a series of flattened, membrane-bound sacs called cisternae, and it has two main faces: the cis face and the trans face.
- The cis face is located closest to the rough endoplasmic reticulum (ER), where proteins and lipids are synthesized and transported to the Golgi in vesicles. This face functions as the receiving side of the Golgi apparatus.
- The trans face, on the other hand, is located farther from the rough ER and faces the plasma membrane. It is considered the “shipping” side of the Golgi apparatus, where the processed proteins and lipids are sorted into vesicles that then travel to their final destinations, such as the plasma membrane, lysosomes, or other parts of the cell.
The Golgi apparatus functions in a polarized manner, with the trans face generally closer to the plasma membrane because this is where the vesicles containing the processed molecules will be directed for exocytosis or other transport. The cis face’s proximity to the rough ER helps with the initial receiving of newly synthesized molecules, and the trans face is where those molecules are sent out to their next destinations.
Thus, the trans face of the Golgi is typically oriented toward the plasma membrane, and this orientation is critical for efficient cellular trafficking and secretion processes.