Osmosis and Water Potential

Osmosis, Osmoregulation, Water Potential, Tonicity

What is osmosis?

The diffusion of water down its concentration gradient across a selectively permeable membrane.

What occurs during osmosis in terms of solute concentration?

Water moves from an area of low solute concentration to an area of high solute concentration.

What does tonicity refer to?

The ability of an extracellular solution to cause a cell to gain or lose water.

What are the three types of solutions cells can be placed in?

Isotonic, Hypertonic, Hypotonic.

What happens to animal cells in an isotonic solution?

There is no net movement of water, maintaining a stable internal environment.

What occurs to cells in a hypertonic solution?

They lose water to their extracellular surroundings, which can cause them to shrivel and die.

What happens to cells in a hypotonic solution?

They gain water, causing animal cells to swell and possibly lyse, while plant cells function optimally.

What is water potential?

A physical property that predicts the direction water will flow, considering solute concentration and physical pressure.

How does water move in relation to water potential?

From areas of high water potential to areas of low water potential.

What is solute potential?

the tendency of water to move by osmosis in response to differences in solute concentrations

What is the solute potential of pure water?

0 MPa.

What does pressure potential refer to?

The physical pressure on a solution, which can be positive or negative relative to atmospheric pressure.

What does 'open air' indicate in terms of pressure potential?

That the pressure potential (𝚿p) is equal to 0 MPa.

What is the value of 1 MPa in bars?

1 MPa is equivalent to 10 bars.

What happens when solute potential increases?

It causes binding to more free water. This leads to a decrease in water potential