6. Cell Membrane & Transport

What type of microorganism has a chitin cell wall, has DNA that is contained in a nucleus, and has ergosterol in its plasma membrane?

______ is a chemical found in eukaryotic cell membranes that regulates fluidity in extreme temperatures.

Which of the following statements best describes what happens to a cell exposed to polymyxins that destroy phospholipids?

a. In an isotonic solution, nothing will happen.

b. In a hypotonic solution, the cell will lyse.

c. Water will move into the cell.

d. Intracellular contents will leak from the cell.

e. Any of the above might happen.

The antibiotic amphotericin B disrupts plasma membranes by combining with sterols; it will affect all of the following cells except

a. Animal cells.

b. Gram-negative bacterial cells.

c. Fungal cells.

d. Mycoplasma cells.

e. Plant cells.

The term fluid mosaic has been used in describing the cytoplasmic membrane. How does each word of that phrase accurately describe our current understanding of a cell membrane?