Cell Membrane Unit Test

Which of the following factors would tend to increase membrane fluidity?

a greater proportion of unsaturated phospholipids

Which means of particle transport requires input to energy from the cell?

active transport

Which of these processes can move a solute against its concentration gradient?

active transport

Diffusion is the movement of molecules from

an area of high concentration to an area of low concentration

The ___________ regulates which substances enter and leave a cell

cell membrane

Which of the following structures serves as the cell's boundary from its environment

cell membrane

Once _________ is reached, roughly equal numbers of molecules move in either direction across a semipermeable membrane, and there is no further change in concentration on either side of the membrane

equilibrium

What membrane-surface molecules are though to be most important as cells recognize each other

glycoproteins

The interior of the phospholipid bilayer is

hydrophobic

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

it exhibits a specificity for a particular type of molecule

Which of the following statements is correct about diffusion?

it is a passive process in which molecules move from a region of higher concentration to lower concentration

When the concentration of molecules on both sides of a membrane is the same, the molecules will

move across the membrane in both directions

the diffusion of water across a selectively permeable membrane is called

osmosis

White blood cells engulf bacteria through what process?

phagocytosis

The cell membrane contains channels and pumps that help move material from one side to another. What are these channels and pumps made of?

proteins

Which of the following is a function of the cell membrane>

regulates which materials enter and leave the cell

A red blood cell placed in pure water will

swell

Diffusion occurs because

the concentration of a solution is never the same throughout a solution

Of the following, which is the most important role of exocytosis?

to release substances from the cell

Unlike the cell membrane, the cell wall is

usually made of tough fibers

an animal cell that is surrounded by fresh water will burst because the osmotic pressure causes

water to move into a cell