osmosis into or out of cells

Question 1

What does the plasma membrane do for a cell?

Answer 1

The plasma membrane separates the cytoplasm from the extracellular fluids.

Question 2

What is the permeability of most plasma membranes?

Answer 2

Most plasma membranes are very permeable to water but much less permeable to solutes.

Question 3

How does the difference in solute concentration affect water movement?

Answer 3

The difference in solute concentrations causes water to move from the less concentrated to the more concentrated solution across the plasma membrane.

Question 4

What is osmosis?

Answer 4

Osmosis is the passive movement of water from a less concentrated solution to a more concentrated solution across a membrane.

Question 5

Are plasma membranes semi-permeable?

Answer 5

Yes, plasma membranes are semi-permeable, meaning they are not freely permeable to all particles.

Question 6

How can a cell change the speed of osmosis?

Answer 6

A cell can change the speed of osmosis by adjusting its plasma membrane’s permeability to water.

Question 7

How can a cell change the direction of osmosis?

Answer 7

A cell can change the direction of osmosis by raising or lowering its concentration of osmotically active solutes.