GRE Subject Test: Biochemistry, Cell, and Molecular Biology › Help with Endoplasmic Reticulum Function
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
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
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.
Which of the following is a function of the smooth endoplasmic reticulum?
Triglyceride production
Protein synthesis
Ribosome production
Macromolecule digestion
The smooth endoplasmic reticulum lacks ribosomes on its surface, meaning it does not participate in protein translation. It does play a key role in the production of various lipids, such as phospholipids and triglycerides.