Biology Chapter 3 - Movement into and out of cells

Diffusion

net movement of particles from a region of high concentration to low concentration, as a result of their random movement

Energy for diffusion

Comes from kinetic energy of random movement of molecules and ions

how can some substances move into and out of cells

by diffusion through cell membrane

State five factors that affect diffusion rates

-temperature
-surface area
-concentration
-steepness in concentration gradient
-distance(inversely proportional)

role of water

solvent in organism to help with excretion, digestion and transport

osmosis

net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partically permeabale cell

Active transport

movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration, using energy from respiration (ATP)

Protein carrier

move molecules or ions across a membrane during active transport