Endoplasmic Reticulum and Golgi Apparatus
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GRE › Endoplasmic Reticulum and Golgi Apparatus
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
Explanation
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.
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
Explanation
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.
Which of the following organelles has the function of storing intracellular calcium?
Endoplasmic reticulum
Nucleolus
Autophagosome
Golgi complex
Lysosome
Explanation
The endoplasmic reticulum, while crucial to protein synthesis, is also an intracellular calcium storage organelle, and calcium can be released in response to signaling cascades as needed. None of the other organelles listed participates in storage of calcium.
Where in the cell does new membrane synthesis take place?
In the endoplasmic reticulum
In the lysosome
In the Golgi apparatus
In the mitochondria
In the ribosomes
Explanation
The endoplasmic reticulum (ER) is the cellular organelle responsible for membrane synthesis. Products from the ER are moved to the Golgi, where they are tagged and shipped off to their final destination. Lysosomes are important for degradation and ribosomes play a role in translation. Mitochondria are for energy production in the form of ATP.
Where in the cell does new membrane synthesis take place?
In the endoplasmic reticulum
In the lysosome
In the Golgi apparatus
In the mitochondria
In the ribosomes
Explanation
The endoplasmic reticulum (ER) is the cellular organelle responsible for membrane synthesis. Products from the ER are moved to the Golgi, where they are tagged and shipped off to their final destination. Lysosomes are important for degradation and ribosomes play a role in translation. Mitochondria are for energy production in the form of ATP.
Which of the following organelles has the function of storing intracellular calcium?
Endoplasmic reticulum
Nucleolus
Autophagosome
Golgi complex
Lysosome
Explanation
The endoplasmic reticulum, while crucial to protein synthesis, is also an intracellular calcium storage organelle, and calcium can be released in response to signaling cascades as needed. None of the other organelles listed participates in storage of calcium.
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
Explanation
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.
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
Explanation
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.
Which component of the Golgi apparatus is primarily responsible for "receiving" proteins to be packaged and modified?
_Cis G_olgi
_Trans G_olgi
_Medial G_olgi
Cisternae
Vacuoles
Explanation
The _cis G_olgi is usually closely apposed to the endoplasmic reticulum, where proteins are synthesized by ribosomes. Once they have left the ribosome, the proteins are already close to the Golgi and are taken up by the cis side of the apparatus. The _trans G_olgi sends the newly packaged proteins out to their final destinations.
Which component of the Golgi apparatus is primarily responsible for "receiving" proteins to be packaged and modified?
_Cis G_olgi
_Trans G_olgi
_Medial G_olgi
Cisternae
Vacuoles
Explanation
The _cis G_olgi is usually closely apposed to the endoplasmic reticulum, where proteins are synthesized by ribosomes. Once they have left the ribosome, the proteins are already close to the Golgi and are taken up by the cis side of the apparatus. The _trans G_olgi sends the newly packaged proteins out to their final destinations.