II. Movement of Materials through II. Movement of Materials through Cell MembraneCell Membrane

SelectivelySelectively permeablepermeable membrane-membrane-

Allows some materials Allows some materials to pass and not othersto pass and not others

Passive Transport Passive Transport

Moving from high Moving from high low concentrationlow concentration

No energy requiredNo energy required

Diffusion-Diffusion-

Molecules of a Molecules of a substance move from substance move from an an area of higher to area of higher to an area of loweran area of lower concentrationconcentration

High High Low Low

Equilibrium- Equilibrium-

Concentration of the Concentration of the molecules will be the molecules will be the same throughout the same throughout the space they occupyspace they occupy

Osmosis-Osmosis-

The diffusion of water The diffusion of water across a semi-across a semi-permeable membranepermeable membrane

Direction of Osmosis Direction of Osmosis

a. Equal water concentration inside and a. Equal water concentration inside and outside cell, cell remains the same (p 99)outside cell, cell remains the same (p 99)

b. High water concentration outside cell, b. High water concentration outside cell, water diffuses in, cell swells (p 99)water diffuses in, cell swells (p 99)

c. High water concentration inside cell, c. High water concentration inside cell, water diffuses out, cell shrinks (p 99)water diffuses out, cell shrinks (p 99)

Facilitated Diffusion (p 101)Facilitated Diffusion (p 101)

Moving from high Moving from high low concentrationlow concentration

No energy requiredNo energy required Carrier molecule is Carrier molecule is

requiredrequired

Active TransportActive Transport

Energy is requiredEnergy is required Two typesTwo types

– 1. low 1. low high high concentrationconcentration

Movement in Vesicles (p 105)Movement in Vesicles (p 105)

Endocytosis- cell Endocytosis- cell engulfing substanceengulfing substance

Phagocytosis- Phagocytosis- engulfing solids engulfing solids Pinocytosis- engulfing Pinocytosis- engulfing liquidsliquids

Movement in Vesicles (p106)Movement in Vesicles (p106)

Exocytosis-Exocytosis- Release of a Release of a

substance from a cellsubstance from a cell Opposite of Opposite of

endocytosisendocytosis

Levels of OrganizationLevels of Organization

CellCell TissueTissue OrganOrgan Organ SystemOrgan System OrganismOrganism