The Cell and its The Cell and its Environment:Environment:

The Cell and its The Cell and its Environment:Environment:

The processes behind The processes behind the movement of the movement of

substances in and out of substances in and out of cellscells

The processes behind The processes behind the movement of the movement of

substances in and out of substances in and out of cellscells

The Cell MembraneThe Cell MembraneThe Cell MembraneThe Cell MembraneThe cell membrane is like the walls of The cell membrane is like the walls of

a space station.a space station.• A.)A.) It must protect its insides from It must protect its insides from

the outside environment; the outside environment; B.)B.) let let in needed materials like food and in needed materials like food and water, and water, and C.)C.) get rid of wastes. get rid of wastes.

• It is the It is the cell membranecell membrane that that controls what enters and leaves controls what enters and leaves the cell.the cell.

The cell membrane is like the walls of The cell membrane is like the walls of a space station.a space station.

• A.)A.) It must protect its insides from It must protect its insides from the outside environment; the outside environment; B.)B.) let let in needed materials like food and in needed materials like food and water, and water, and C.)C.) get rid of wastes. get rid of wastes.

• It is the It is the cell membranecell membrane that that controls what enters and leaves controls what enters and leaves the cell.the cell.

The cell membrane is The cell membrane is selectively selectively permeable!!!permeable!!!

The cell membrane is The cell membrane is selectively selectively permeable!!!permeable!!!

This means that some substances can This means that some substances can pass through it and some can’t.pass through it and some can’t.

Substances can move into and out of a Substances can move into and out of a cell by one of three methods: Diffusion, cell by one of three methods: Diffusion, Osmosis, or Active TransportOsmosis, or Active Transport

This means that some substances can This means that some substances can pass through it and some can’t.pass through it and some can’t.

Substances can move into and out of a Substances can move into and out of a cell by one of three methods: Diffusion, cell by one of three methods: Diffusion, Osmosis, or Active TransportOsmosis, or Active Transport

Passive Transport:Passive Transport:Passive Transport:Passive Transport:

Is the movement of substances Is the movement of substances through a cell membrane through a cell membrane withoutwithout using energyusing energy

Is the movement of substances Is the movement of substances through a cell membrane through a cell membrane withoutwithout using energyusing energy

Diffusion (Diffusion (passive transportpassive transport))Diffusion (Diffusion (passive transportpassive transport))

Is the process by which molecules of a Is the process by which molecules of a substance move from an area of substance move from an area of high high concentration to an area of low concentration to an area of low concentrationconcentration

For example, if oxygen concentration is For example, if oxygen concentration is higherhigher outside a cell than inside, the outside a cell than inside, the oxygen molecules will oxygen molecules will diffuse intodiffuse into the the cell until the concentration inside is cell until the concentration inside is equal to the outside.equal to the outside.

Is the process by which molecules of a Is the process by which molecules of a substance move from an area of substance move from an area of high high concentration to an area of low concentration to an area of low concentrationconcentration

For example, if oxygen concentration is For example, if oxygen concentration is higherhigher outside a cell than inside, the outside a cell than inside, the oxygen molecules will oxygen molecules will diffuse intodiffuse into the the cell until the concentration inside is cell until the concentration inside is equal to the outside.equal to the outside.

Osmosis (Osmosis (passive transportpassive transport))Osmosis (Osmosis (passive transportpassive transport))

Is theIs the diffusiondiffusion ofof waterwater through a selectively through a selectively permeable membranepermeable membrane

Is theIs the diffusiondiffusion ofof waterwater through a selectively through a selectively permeable membranepermeable membrane

Active Transport:Active Transport:isis the movement of substances through the cell the movement of substances through the cell

membrane using energymembrane using energy

Active Transport:Active Transport:isis the movement of substances through the cell the movement of substances through the cell

membrane using energymembrane using energy

Two main methods ofTwo main methods of active transport:active transport: 1.)1.) using using transport proteinstransport proteins to pick up to pick up

substances like salts or calcium outside the cell substances like salts or calcium outside the cell and carry them inside or carry them outside the and carry them inside or carry them outside the cell the same waycell the same way

2.)2.) EngulfingEngulfing where the cell membrane where the cell membrane surrounds a particle and forms a vacuole inside surrounds a particle and forms a vacuole inside the cellthe cell

Two main methods ofTwo main methods of active transport:active transport: 1.)1.) using using transport proteinstransport proteins to pick up to pick up

substances like salts or calcium outside the cell substances like salts or calcium outside the cell and carry them inside or carry them outside the and carry them inside or carry them outside the cell the same waycell the same way

2.)2.) EngulfingEngulfing where the cell membrane where the cell membrane surrounds a particle and forms a vacuole inside surrounds a particle and forms a vacuole inside the cellthe cell