Exam 7: Membrane Structure and Function

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. At the beginning of the U-tube experiment illustrated above, which of the following statements is true?

The force driving simple diffusion is ________, while the energy source for active transport is ________.

According to the fluid mosaic model, a membrane ________.

Which of the following structures would decrease the electrochemical gradient across a membrane?

In which of the following environments would there be the greatest need for osmoregulation?

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in ________.

For a protein to be an integral membrane protein, it would have to be ________.

When a cell is in equilibrium with its environment, which of the following processes occurs for substances that can diffuse through the plasma membrane?

Which of the following statements correctly describes osmosis?

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. In the U-tube experiment illustrated above, which of the following statements correctly describes side B at equilibrium?

Which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane?

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane?

Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water ________.

What kinds of molecules pass through a cell membrane most easily?

In what way do the membranes of a eukaryotic cell vary?

Diffusion of ions across membranes through specific ion channels is driven by ________.

The difference between pinocytosis and receptor-mediated endocytosis is that ________.

Why are lipids and proteins free to move laterally in membranes?

Match the labelled component of the cell membrane in the figure with its description. - Which component in the accompanying figure is hydrophilic?

Five dialysis bags, constructed of a type of membrane that is permeable to water and impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed), and the percent change in mass of each bag was graphed. Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes?