2. Cell Chemistry & Cell Components

A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually found in a cell's plasma membrane. The protein in the plasma membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the __________.

Consider a protein that is made in the rough endoplasmic reticulum. You observe that when the synthesis of the protein is completed, the protein is located in the ER membrane. Where else in the cell might this protein be found?

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________.

Which structure is part of the endomembrane system? (A) mitochondrion (B) Golgi apparatus (C) chloroplast (D) centrosome

Which structure is not part of the endomembrane system? a. nuclear envelope b. chloroplast c. Golgi apparatus d. plasma membrane

Which of the following results provided evidence of a discrete nuclear localization signal somewhere on the nucleoplasmin protein? a. The nucleoplasmin protein was small and easily slipped through the nuclear pore complex. b. After cleavage of the nucleoplasmin protein, only the tail segments appeared in the nucleus. c. Removing the tail from the nucleoplasmin protein allowed the core segment to enter the nucleus. d. The SRP bound only to the tail of the nucleoplasmin protein, not the core segment.

Molecular zip codes direct molecules to particular destinations in the cell. How are these signals read? a. They bind to receptor proteins. b. They enter transport vesicles. c. They bind to motor proteins. d. They are glycosylated by enzymes.