IGCSE Movement in and out of cells

What is diffusion?

net movement of particles from an area of high concentration to an area low concentration down a concentration gradient, resulting in equilibrium

What is osmosis?

diffusion of water from an high water to a low water potential down a concentration gradient through a partially permeable membrane

What is a hypotonic solution?

dilute solution

What happens when a cell is placed into a hypotonic solution?

Water moves in and cell becomes turgid

What is a isotonic solution?

equilibrium between that and the cell

What happens when a cell is placed into a isotonic solution?

nothing

What is a hypertonic solution?

concentrated solution

What happens when a cell is placed into a hypertonic solution?

water moves out and cell becomes plasmolysed

What is active transport?

Movement of molecules from a low concentration to a high concentration against a concentration gradient, requires energy

How does active transport work? step 1

molecules outside the cell in low concentration attach to carrier proteins

How does active transport work? step 2

adenosine triphosphate converts to adenosine diphosphate and energy is released

How does active transport work? step 3

the carrier protein changes shape and releases the molecule into the cell