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Today’s Bell RingerToday’s Bell Ringer

1. Please turn in your cell analogy projects.2. Work individually on the chart. Compare

and contrast animal and plant cells, and eukaryotes and prokaryotes.

3. You may use you books and notes if necessary.

4. Keep your chart, we will go over it when the chime rings.

5. Quietly check you folder if there is time! 6. Thanks!

1. Please turn in your cell analogy projects.2. Work individually on the chart. Compare

and contrast animal and plant cells, and eukaryotes and prokaryotes.

3. You may use you books and notes if necessary.

4. Keep your chart, we will go over it when the chime rings.

5. Quietly check you folder if there is time! 6. Thanks!

Time is Up!Time is Up!

Passive & Active TransportPassive & Active TransportChapter 4

SOL 4 a, b, & dChapter 4

SOL 4 a, b, & d

Today’s Question:Today’s Question:

How do molecules cross the cell membrane?

How do molecules cross the cell membrane?

I. Transport across the CMI. Transport across the CM1. Passive transport

• Diffusion• Facilitated diffusion• Osmosis

2. Active transport• Ion Pumps• Exocytosis• Endocytosis

• Phagocytosis• Pinocytosis• Receptor-Mediated

1. Passive transport• Diffusion• Facilitated diffusion• Osmosis

2. Active transport• Ion Pumps• Exocytosis• Endocytosis

• Phagocytosis• Pinocytosis• Receptor-Mediated

No Energy Required

Require Energy

II. Passive TransportII. Passive Transport

1. DIFFUSION (AKA “simple diffusion”)

• Molecules move from an area of high concentration, to an area of low conc.• Moves DOWN the conc.

Gradient• Molecules must be able to cross the

cell membrane.

1. DIFFUSION (AKA “simple diffusion”)

• Molecules move from an area of high concentration, to an area of low conc.• Moves DOWN the conc.

Gradient• Molecules must be able to cross the

cell membrane.

Diffusion AnimationDiffusion Animation

II. Passive TransportII. Passive Transport

2. FACILITATED DIFFUSION:Substances that are not soluble in lipids need help to get across the Cell Memebrane.

“Carrier” proteins help them to get.

Molecules move from high concentration to lowStill moving DOWN conc. gradient.

2. FACILITATED DIFFUSION:Substances that are not soluble in lipids need help to get across the Cell Memebrane.

“Carrier” proteins help them to get.

Molecules move from high concentration to lowStill moving DOWN conc. gradient.

Facilated Diffusion

II. Passive TransportII. Passive Transport

3. OSMOSIS Special term applied to the

diffusion of WATER molecules across the CM.

Just like simple diffusion Water molecules move from area of high

water concentration to area of low water concentration

Osmosis Animation

3. OSMOSIS Special term applied to the

diffusion of WATER molecules across the CM.

Just like simple diffusion Water molecules move from area of high

water concentration to area of low water concentration

Osmosis Animation

OsmosisOsmosis

Osmosis happens in your body ALL THE TIME

Because of its importance, there are 3 special terms dealing with water solutions Isotonic Hypertonic Hypotonic

Osmosis happens in your body ALL THE TIME

Because of its importance, there are 3 special terms dealing with water solutions Isotonic Hypertonic Hypotonic

III. OsmosisIII. Osmosis

1. ISOTONIC SOLUTION: Same concentraion of “stuff” dissolved in surrounding solution as inside the cell.

1. No net movement of water across the membrane.

• Cell stays the same size.• State of EQUILIBRIUM

1. ISOTONIC SOLUTION: Same concentraion of “stuff” dissolved in surrounding solution as inside the cell.

1. No net movement of water across the membrane.

• Cell stays the same size.• State of EQUILIBRIUM

III. OsmosisIII. Osmosis

2. HYPOTONIC SOLUTION: A solution surrounding a cell that has less dissolved solute than in the cell.

H2O moves in.• Cell grows in size.• Think of a Hippo (he’s round,

plump, looks like he might burst…)

2. HYPOTONIC SOLUTION: A solution surrounding a cell that has less dissolved solute than in the cell.

H2O moves in.• Cell grows in size.• Think of a Hippo (he’s round,

plump, looks like he might burst…)

III. OsmosisIII. Osmosis3. HYPERTONIC SOLUTION: A solution

surrounding a cell that has more dissolved solute than the cell.1. H2O Moves out of the cell.

• To help you remember:

• The “e” in hypErtonic = H2O Exits

• Cell shrinks in size.

3. HYPERTONIC SOLUTION: A solution surrounding a cell that has more dissolved solute than the cell.1. H2O Moves out of the cell.

• To help you remember:

• The “e” in hypErtonic = H2O Exits

• Cell shrinks in size.

isotonic solution hypertonic solution hypotonic solution

10 microns

equal movement of waterinto and out of cells

net water movement out of cells

net water movement into cells

1. Mov’t of molecules AGAINST (up) a concentration gradient.

2. Requires ENERGY (ATP)Like pushing a boulder up a hill.

3. Transport proteins are needed to move molecules across CM.These proteins use up energy to work.

1. Mov’t of molecules AGAINST (up) a concentration gradient.

2. Requires ENERGY (ATP)Like pushing a boulder up a hill.

3. Transport proteins are needed to move molecules across CM.These proteins use up energy to work.

IV. Active TransportIV. Active Transport

IV. Active TransportIV. Active Transport4. Ex. Of Active Transport: ION PUMPS

Na+/K+ pump

Protein’s shape changes.

See video clip

Sodium-Potassium Pump

4. Ex. Of Active Transport: ION PUMPS

Na+/K+ pump

Protein’s shape changes.

See video clip

Sodium-Potassium Pump

V. Movement in VesiclesV. Movement in Vesicles1. EXOCYTOSIS: mov’t of large

molecules across the CM by a vesicle, OUT OF the cell.

1. EXOCYTOSIS: mov’t of large molecules across the CM by a vesicle, OUT OF the cell.

V. Movement in VesiclesV. Movement in Vesicles

2. ENDOCYTOSIS: mov’t of large substances across the CM by a vesicle, INTO the cell.

2. ENDOCYTOSIS: mov’t of large substances across the CM by a vesicle, INTO the cell.

3. Three types of Endocytosis

3. Three types of Endocytosis

A. PHAGOCYTOSIS = ingestion or “eating” of molecules by the cell.

To help you remember: PHAGO my EGO.

This is how your immune cells destroy bacteria…they eat them!!!

Watch the phagocytosis animation

A. PHAGOCYTOSIS = ingestion or “eating” of molecules by the cell.

To help you remember: PHAGO my EGO.

This is how your immune cells destroy bacteria…they eat them!!!

Watch the phagocytosis animation

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

human immune system ingests whole bacteria

3. Three types of Endocytosis

3. Three types of Endocytosis

B. PINOCYTOSIS = ingestion of liquid by a cell.

To help you remember: PINO COLADA.

B. PINOCYTOSIS = ingestion of liquid by a cell.

To help you remember: PINO COLADA.

3. Three types of Endocytosis

3. Three types of Endocytosis

C. RECEPTOR-MEDIATED: cells ingest large molecules using receptor sites specific to the molecules being ingested.

C. RECEPTOR-MEDIATED: cells ingest large molecules using receptor sites specific to the molecules being ingested.

Exocytosis and Endocytosis

Exocytosis and Endocytosis

Phagocytosis and Exocytosis Phagocytosis and Exocytosis