Movement in and out of cells

spread

cover or cause to cover a large area

diffuse

to spread freely or widely

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Photosynthesis

Conversion of light energy from the sun into chemical energy.

Stomata

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move

waste product

A substance made from the chemical reaction that is left over and not used.

Respiration

The process by which cells break down simple food molecules to release the energy they contain.

rate of diffusion

amount of gas diffusing through a given area over a given time

Solute

A substance that is dissolved in a solution.

solvent

the substance in which the solute dissolves

Partially permeable membrane

A membrane that lets some molecules through it, but not others.

Visking tubing

Type of synthetic tubing that is partially permeable, allowing only water and some other small molecules to pass through its pores.

high water potential

dilute solution

low water potential

concentrated solution

Osmosis

Diffusion of water molecules from a region of higher water potential to a region of lower water potential, through a partially permeable membrane.

Cytoplasm

a solution of proteins and other substances in water

swell

increase in size or volume

burst

explode

shrink

decrease in size, range, or extent

turgid

swollen

flaccid

limp, not firm or strong

plasmolysed

the condition of a plant cell that has lost so much water that its cytoplasm shrinks and pulls the cell membrane away from the cell wall

active transport

the movement of molecules and ions in or out of a cell through a cell membrane against a concentration gradient, using energy from respiration

kinetic energy

energy because of motion