Cell Membrane Test Review I

Which of the following phrases best describes active transport?

• moves substance against concentration gradient

• does not use chemical energy

• forms a vesicle around a large particle

• relies on diffusion of materials

Refer to the illustration above. The structure labeled A is composed of

• lipids.

• carbohydrates.

• proteins.

• DNA.

All of the following are examples of lipids except

• oil.

• starch.

• cholesterol.

• candle wax.

What is a phospholipid composed of?

• a polar head and a nonpolar tail

• a nonpolar head and a polar tail

• a polar head and tail

• a nonpolar head and tail

A solution that is hypotonic to a cell has

• more solutes than the cell.

• fewer solutes than the cell.

• the same concentration of solutes as the cell.

• too many solutes.

What is the term for the diffusion of water across a semipermeable membrane?

• osmosis

• equilibrium

• transport

• isotonic

Which phrase best describes the property of selective permeability?

• some molecules pass

• all ions pass

• large molecules pass

• all molecules pass

Molecules that are attracted to water are said to be hydrophilic.

• True

• False

The movement of molecules down a concentration gradient through transport proteins in the cell membrane is a type of

• selective transport.

• osmosis.

• facilitated diffusion.

• energy expenditure.

Proteins that serve as tunnels for specific substances through the lipid bilayer are

• cell-surface markers.

• transport proteins.

• receptor proteins.

• enzymes.