Movement in and out of cells: Diffusion, osmosis, active transport

Diffusion, osmosis, active transport

Diffusion

Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration due to the random movement of particles.

Solvent

A solvent is any substance, usually liquid, which is capable of dissolving one or several substances, thus creating a solution

Solute

the minor component in a solution, dissolved in the solvent

Osmosis

Osmosis is the diffusion of water molecules from a region of higher water potential (more dilute) to a region of lower water potential (more concentrated), through a partially permeable membrane

What does high water potential mean?

More water molecules and less solute molectules (dilute)

Turgor pressure

Turgor pressure is the force exerted by the fluid inside a cell against its cell wall, primarily driven by osmosis. It's the pressure within a plant cell that pushes the vacuole against the cell wall. This pressure plays a vital role in maintaining cell shape and support for the plant.

Hypotonic solution

High water potential: more water than solute

Hypertonic solution

Low water potential: more solute than water

Why do animal cells burst when too much water diffuses in but plant cells don’t?

Plant cells have a strong cell wall made of cellulose, while animal cells don’t

Another word for ‘burst’ or ‘dead’

lysed: to lyse: undergo lysis

Suggest why eating too much salt can lead to high blood pressure

Eating too much salt can lead to high blood pressure primarily because it causes the body to retain water, increasing the volume of blood and the pressure against artery walls

What happens if you place a plant cell in a hypotonic solution?

There is a net movement of water into the cell which causes the plant cell to become turgid (it does not burst because of the strong cell wall)

What happens if you place an animal cell in a hypertonic solution?

There is a net movement of water out of the cell which causes the animal cell to shrink (crenate)