D2.3.3 Water movement by osmosis into or out of cells

Define osmosis.

Osmosis is the passive movement of water molecules across a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration.

What is a semi-permeable membrane?

A membrane that allows water to pass but restricts solutes.

Why does water move during osmosis?

Water moves to balance solute concentrations on both sides of the membrane.

What happens during equilibrium in osmosis?

Water moves until concentrations are equal on both sides of the membrane.

What can happen to animal cells with excessive water intake?

They can burst (lyse) because they lack a cell wall for support.

What occurs in an isotonic environment?

There is no net movement of water, but water molecules continue to move across the membrane.

Why is osmosis important for cell survival?

Osmosis regulates water balance, preventing cells from bursting or shrinking.

How do root cells use osmosis?

Root cells absorb water from the soil through osmosis.

What is a medical application of osmosis?

Isotonic solutions are used in IV drips to prevent damage to blood cells.

What is the difference between hypotonic and hypertonic?

Hypotonic has lower solute concentration compared to hypertonic, which has higher solute concentration.

What is the key factor that drives osmosis?

The concentration gradient.

Can osmosis occur without a membrane?

No, osmosis specifically involves movement across a semi-permeable membrane.

Give an example of osmosis in action.

Root cells absorbing water from the soil.

What happens to a cell in a hypertonic solution?

The cell will shrink or undergo crenation due to water moving out.

What happens to a cell in a hypotonic solution?

The cell will swell and may burst due to water moving in.

What is the ultimate goal of osmosis?

To achieve equilibrium where solute concentrations are equal on both sides.

Does osmosis require energy?

No, osmosis is a passive process.