Exam 5: Cell Membrane Structure and Function

Imagine that you fill a shallow tray with water and place a drop of red ink in one end of the tray and a drop of green ink in the other end. Which of the following is TRUE at equilibrium?

More than half a century ago, two cell biologists published details of their research involving isolated membrane vesicles from chloroplasts. Normally, the fluid inside these vesicles is near neutral. In an experiment, these membrane vesicles were soaked in an acidic solution (pH 4) until the inside of the vesicle also became pH 4. Based on the details provided in this scenario, by what mechanism could hydrogen ions have crossed the vesicle membrane, and what do you think happened at the molecular level?

Osmosis moves water from a region of

Which of the following would NOT be found in a membrane?

Which of the following accounts for the fluid aspect of the fluid mosaic model of plasma membranes?

Facilitated diffusion and active transport both require for the movement of molecules across the membrane.

Two similar- sized animal cells are placed in a 0.5% sucrose solution. Cell A enlarges for a while and then stops; cell B continues to enlarge and finally ruptures. Which of the following must have been TRUE at the beginning of the experiment?

Phospholipids contain two different parts: a head and a pair of _ tails.

The blood plasma of a man who drinks salt water will become _ to his red blood cells, whereas the red blood cells will be to the blood plasma.

Active transport requires all of the following EXCEPT

All of the following may influence the rate of simple diffusion across a selectively permeable membrane EXCEPT the

Which of the following types of membrane proteins are responsible for facilitated diffusion?

In general, which of the following is (are) largely responsible for moving substances across the plasma membrane, communicating with other cells, and identifying the cell?

Based on these four illustrations of diffusion, which mode would most likely be used to transport oxidized zinc (which has a charge of +2) through the cell membrane?

Molecules assisted by carrier proteins may cross a selectively permeable membrane by