GRE Subject Test: Biochemistry, Cell, and Molecular Biology › Help with Golgi Apparatus Function
Which of the following GTP-binding proteins is associated with COPI during vesicle assembly and budding in the cis-Golgi?
ADP ribosylation factors (ARFs)
SAR1A
Glycosidases
Soluble NSF attachment protein receptor (SNARE)
ATPases
The correct answer is ADP ribosylation factors (ARFs). ARFs are active when bound by GTP, and inactive when bound by GDP. The active GTP-bound form of ARF binds the vesicle coat protein 1 (COPI), to faciliate vesicle budding from the cis-Golgi face.
What is the primary function of the Golgi apparatus?
All of these are primary functions of the Golgi apparatus
Protein sorting
Post-translational modifications of proteins
Maintaining the secretory pathway
The Golgi apparatus is a complex organelle with many various functions. These functions are primarily dedicated to protein modification, protein packaging, and protein sorting. Some of post-translational modifications that take place in this organelle include glycosylation and phosphorylation. The Golgi apparatus is an important relay in the secretory pathway, as it produces the vesicles that contain most secreted peptides.
Each of the following functions are associated with the Golgi apparatus, except __________.
Contains resident proteins required for the electron transport chain (ETC)
Delivery of proteins to the lysosome
Delivery of proteins to the plasma membrane
Post-translational modifications to proteins to aid in their sorting
Formation of proteoglycans for the extracellular matrix
The Golgi apparatus is considered the post office of the cell; proteins are received, sorted, modified, and sent to their final cellular destination. The proteins required for the electron transport chain are localized to the mitochondria, and are not within the Golgi apparatus, thus this is the correct selection.