Membrane video 2 quiz

In what way do the membranes of a eukaryotic cell vary?

Certain proteins are unique to each membrane.

Which of the following statements correctly describes osmosis?

In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.

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

It exhibits specificity for a particular type of molecule like Na+/Glucose transporters

Which of the following statements about diffusion is true?

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

When a cell is in equilibrium with its environment, which of the following processes occurs for substances that can diffuse through the plasma membrane?

There is random movement of substances into and out of the cell.

The force driving simple diffusion is ________, while the energy source for active transport is ________.

a concentration gradient; ATP hydrolysis

Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? The animal cell is in ________.

an isotonic solution, and the plant cell is in a hypotonic solution

Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water

is hypotonic and the salt solution is hypertonic to the cells of the celery stalks

Which of the following membrane activities requires energy from ATP hydrolysis?

movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid

A sodium-potassium pump ________.

moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis