Exam 5: Membrane Structure and Function

Which of the following situations is most likely to produce a heart attack?

In the cell pictured, there is no net movement of water. The amount leaving the cell and entering the cell is the same. In what type of environment is this cell found?

Why does this model of a phospholipids bilayer in Fig. 2 not 'work'?

Whether a molecule can cross the plasma membrane depends upon

A 10% glucose solution is placed in the thistle tube. The thistle tube is placed in a beaker that contains a 5% glucose solution. There is a differentially permeable membrane across the broad end of the tube, which is permeable to water but not to the sugar glucose. What will occur over time to the water? To the solute?

Before boarding an airplane on a commercial flight, the traveler must show personal identification and a ticket to airport security. The traveler must then remove his shoes and place any carry-on items on the belt of an x-ray machine before walking through the checkpoint. How is the passage of molecules through a membrane similar to travelers passing through airport security?

The major functions of the plasma membrane do NOT include

Which process is responsible for moving cellular wastes across the cell membrane and out of the cell?

Which type of cellular process will most likely be used by an amoeba in order to obtain food?

All life forms currently have a basic cell membrane so we presume that the earliest forms of life had this "fence" isolating the internal organization from the external chaos. It is likely that the primordial environment was acidic. In order for a cell to function in this type of environment, the cell membrane would have to include

What type of transport mechanism is required to move sodium ions against their concentration gradient?

Design an experiment that illustrates how any one of these factors (temperature, pressure, molecule size) may affect the rate of diffusion.

A 10% glucose solution is placed in the thistle tube. The thistle tube is placed in a beaker that contains a 5% glucose solution. Where is the highest concentration of water found?

Study the series of pictures to identify the process through which materials are being transported across the membrane. Explain how you arrived at your answer.

Proteins in a membrane are

Fluidity of a membrane increases as the percentage of unsaturated fatty acids in the phospholipids goes up.

In the cells that line the lumen of the small intestine, gap junctions keep materials from the digestive tract from slipping between the cells and entering the tissues.

Having similar ____________ would allow tissues and organs to be transplanted easily.

Which statement is true about the plasma membrane?

The process by which cholesterol is transported into the cell by the binding of LDL to its receptor and the internalization of the receptor-LDL complex is