Reference no: EM1390338

7. Assume you study a transmembrane protein that is trafficked through the endoplasmic reticulum but ultimately "lives" in the plasma membrane. Suppose the domain of this protein which is exposed on the outer face of the endoplasmic reticulum membrane was covalently (and specifically) labeled with a fluorescent dye in a living cell. When the protein is distributed among cellular compartments, where would you expect the dye to be located?
a) The dye will be on the outer face of the endoplasmic reticulum, on the inner face of the Golgi apparatus, and on the extracellular face of the plasma membrane.
b) The dye will be on the inner face of the endoplasmic reticulum, on the inner face of the Golgi apparatus, and on the intracellular face of the plasma membrane.
c) The dye will be on the outer face of the endoplasmic reticulum, on the outer face of the Golgi apparatus, and on the intracellular face of the plasma membrane.
d) The dye will be on the outer face of the endoplasmic reticulum, on the outer face of the Golgi apparatus, and on the extracellular face of the plasma membrane.
8. Eukaryotic cells manufacture fibrous cytoskeletal proteins that function in the cytoplasm to maintain cell shape by providing structural support, move materials within the cell, and move the entire structure. Which of the following predictions about protein synthesis, processing, and trafficking applies to the general class of cytoskeletal proteins?
a) They would be glycosylated in the Golgi apparatus.
b) They might travel to the nucleus in a transport vesicle with a specific zip code.
c) They would initially contain signal sequences that would allow their entrance into the endoplasmic reticulum.
d) They would be manufactured on free ribosomes in the cytoplasm.
9. Which of the following would you predict would happen to a secretory protein if the enzyme that cleaves off the signal peptide were inhibited?
a) The secretory protein would be anchored in the ER membrane by the signal peptide and would end up in cellular membranes.
b) The ribosome would remain in the cytoplasm and the secretory protein would be released from the ribosome as a cytosolic protein.
c) The secretory protein would be translated at the ER membrane but would not be inserted into the membrane.
10. A very large carbohydrate is tagged with a fluorescent marker and placed in the extracellular environment surrounding a eukaryotic cell. The cell ingests the carbohydrate via endocytosis. Upon viewing the cells under a fluorescent microscope, which of the following cellular substructures is
most likely to be fluorescently labeled?
a) nucleus
b) lysosomes
c) ribosomes
d) mitochondria
e) peroxisomes