CHAPTER 7 MULTIPLE CHOICE VERSION

Each of the following is a function of membranes except

information storage.

Of the following molecules, which would you predict diffuses most readily across membranes?

oxygen

Each of the following is a type of cell - cell junctions except

All are cell - cell junctions.

Starting with shredded spinach leaves, you follow a procedure that separates cellular organelles into different fractions. To identify the fraction that contains the mitochondria, you should test for the presence of

electron transport proteins

Each of the following is typical characteristics of an integral membrane protein transmembrane segment except

amphipathic

In response to temperature changes, cell membranes change state to become more solid or more fluid by undergoing

a phase transition.

The composition of lipids in the outer and inner monolayers of cell membrane lipid bilayers is

asymmetrical; i.e., different in each monolayer.

The most prominent lipids in animal cell membranes are

phospholipids.

Which of the following would you expect to find predominating in the plasma membrane of a unicellular eukaryotic organism thriving in glacier ice?

16 carbon long fatty acids with 3 double bonds

Cholesterol

buffers membrane fluidity by increasing fluidity at low temperature and decreasing fluidity at high temperature.

Using a laser beam to inactivate fluorescence dye molecules connected to proteins or lipids on a cell membrane is called

photobleaching.

Predict which of the following lipid characteristics would be most important to form the best liposomes for delivering a drug into a cell.

It is amphipathic

Which of the following is a sterol-like lipid associated with plant cell membranes?

phytosterol

E. coli uses which of the following enzymes to regulate membrane fluidity?

desaturase

Lipid rafts are associated with which of the following activities?

All of the above are correct.

The technique that separates denatured proteins based on size is

SDS-PAGE

Localized regions of plasma membranes that contain cholesterol and proteins involved in cell signaling are known as

lipid rafts

Which of the following types of protein would be most easily removed from a membrane by changing pH or ionic strength?

peripheral protein

FRAP has revealed that some proteins move in cell membranes much slower than they move in reconstituted liposomes. Which of the following could account for limited mobility of proteins in cell plasma membranes?

All could limit protein mobility.

Which of the following is true about glycosylated plasma membrane proteins?

The carbohydrates can be detected experimentally with ferritin-linked lectins