Organelle function and intracellular protein trafficking pathways tested on USMLE Step 1.
33 cards · basic cards · AI-written, checked twice. Edit anything.
- What is the primary function of the rough endoplasmic reticulum (RER)?
Show answer
Synthesizes and folds proteins destined for secretion, the plasma membrane, or other organelles- What is the primary function of the smooth endoplasmic reticulum (SER)?
Show answer
Lipid/steroid synthesis and detoxification of drugs and toxins- Which type of cell has abundant smooth ER?
Show answer
Steroid hormone-producing cells (e.g., adrenal cortex, Leydig cells)- Which type of cell has abundant rough ER?
Show answer
Cells that secrete large amounts of protein, such as plasma cells- What is the general function of the Golgi apparatus?
Show answer
Modifies, sorts, and packages proteins and lipids for their final destination- Which organelle does the cis face of the Golgi apparatus face?
Show answer
The endoplasmic reticulum- Which structure does the trans face of the Golgi apparatus face?
Show answer
The plasma membrane- In the Golgi, lysosomal enzymes are tagged with ____ to direct them to the lysosome.
Show answer
mannose-6-phosphate- I-cell disease is caused by a deficiency of which enzyme?
Show answer
N-acetylglucosaminyl-1-phosphotransferase- What happens to lysosomal enzymes in I-cell disease?
Show answer
They are secreted out of the cell instead of being delivered to lysosomes- Proteins bearing the ____ sequence are retrieved and retained in the endoplasmic reticulum.
Show answer
KDEL- What does the signal recognition particle (SRP) do?
Show answer
Binds a signal sequence on a nascent protein and directs the ribosome to the rough ER- COPII-coated vesicles transport cargo in which direction?
Show answer
From the ER to the Golgi (anterograde)- COPI-coated vesicles transport cargo in which direction?
Show answer
From the Golgi back to the ER (retrograde)- What proteins do free (cytosolic) ribosomes synthesize?
Show answer
Proteins that stay in the cytosol or are imported into the nucleus, mitochondria, or peroxisomes
FlashKeepers