Answer: Retained in the ER lumen.
- A Secreted out of cell
- B Targeted to lysosomes
- C Retained in the ER lumen
- D Sent to mitochondria
Correct answer: C. Retained in the ER lumen
Explanation: KDEL (Lys-Asp-Glu-Leu) is the ER retention signal. Proteins with KDEL are retrieved from the Golgi and retained in the ER.
Animal cell structure with major organelles labeled. Image: LadyofHats (Mariana Ruiz), Public Domain, via Wikimedia Commons.
Concept context
Cell theory, prokaryotic vs eukaryotic cells, organelles and their functions. Foundation of all biology.