Exam 5: Cell Membrane Structure and Function

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

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?

The cytoplasm of a certain cell, such as a neuron, already has a high concentration of K+ ions. How can K+ ions continue to enter the cell?

The ________ portion of the cell membrane is responsible for the isolating function of the membrane, while the ________ portion regulates exchange and communication with the environment.

Adhesion of cells within animal tissues is accomplished by cell-to-cell junctions called:

When substances move through a plasma membrane and down gradients of concentration, this is called:

Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that:

The urinary bladder is protected from leaking due to cell-to-cell junctions called:

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

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

When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because:

When very small viruses infect a plant cell by crossing its membrane, the viruses often spread rapidly throughout the entire plant without crossing additional membranes. Explain how this occurs.

The blood plasma of a man who drinks saltwater will become ________ to his red blood cells, whereas the red blood cells will be ________ to the blood plasma.

The diffusion of water molecules across a selectively permeable membrane is called:

The compounds in biological membranes that form a barrier to the movement of materials across the membrane are:

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

According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids?

What prevents your immune system from attacking your own cells?

The hydrophobic tails of a phospholipid bilayer are oriented toward the:

The gases O2 and CO2 enter or leave a plant cell by: