Intracellular Traffic
1. Polypeptides get from the ER to the Golgi complex because of:
a. An N-terminal amino acid sequence
b. An O-linked oligosaccharide
c. A ribosome
d. Secretion
e. An N-linked oligosaccharide
2. O-linked glycosylation occurs at the:
a. Smooth ER
b. Rough ER
c. Golgi complex
d. Secretory vesicles
e. Nucleus
3. Which of the following is not associated with the ER?
a. Carbohydrate metabolism
b. Membrane synthesis
c. Oxidation of foreign substances
d. Protein processing
e. None of the above
4. Which of the following is not a function of the Golgi complex?
a. Formation of lysosomes
b. Synthesis of lysosomal enzymes
c. Formation of the plasma membrane
d. Synthesis of hyaluranate and pectin
e. None of the above
5. Which one of the following is not true of material entering through a coated pit?
a. Receptor and ligand return to the plasma membrane
b. Receptor and ligand are degraded by a lysosome
c. Receptor and ligand move to the opposite side of the cell
d. Receptor and ligand are stored in vesicles
e. None of the above
6. Mannose-6-phosphate targets proteins for incorporation into:
a. Lysosomes
b. Golgi complex
c. The plasma membrane
d. Mitochondria
e. Secretory vesicles
7. Ethyl alcohol is detoxified in the liver. You would expect alcohol to have which of the following effects on liver cells?
a. Nuclear degeneration
b. Growth of the smooth ER
c. Increased lysosomes
d. Growth of the rough ER
e. None of the above
8. Many bacterial pathogens require iron to grow. Human cells sequester the iron using:
a. Phagocytosis
b. Receptor-mediated endocytosis
c. Transitional vesicles
d. Secretory vesicles
e. None of the above
9. Which of the following is not correctly matched?
a. Phagocytosis-particles
b. Pinocytosis-soluble macromolecules
c. Exocytosis-waste products
d. Coated pits-insulin
e. None of the above
10. Which of the following first binds to the ER for protein synthesis?
a. Growing polypeptide
b. mRNA
c. Ribosome subunits
d. Signal sequence
e. Signal-recognition particle
11. The following steps occur during pinocytosis. What is the third step?
a. Residual bodies form
b. Lysosomes form secondary lysosomes
c. A vesicle forms
d. Secondary lysosome fuses with plasma membrane
e. Membrane randomly folds
12. In a pulse-chase experiment, where would you find a H-3 labelled mannose molecule?
a. In the ER
b. In the plasma membrane
c. Outside the cell
d. In secretory vesicles
e. In the Golgi complex
13. In a pulse-chase experiment, where would you find the radioactive label in a cell whose secretion has been inhibited?
a. In the ER
b. In the plasma membrane
c. Outside the cell
d. In secretory vesicles
e. In the Golgi complex
14. Vesicles formed from the Golgi complex can become any of the following except:
a. Storage vesicles
b. Lysosomes
c. Part of the plasma membrane
d. Mitochondria
e. None of the above
15. In a pulse-chase experiment, where would you find clathrin triskelions?
a. In the ER
b. In the plasma membrane
c. Outside the cell
d. In secretory vesicles
e. In the Golgi complex