Cellular Transport

How Your Cells Eat, Drink and be Merry!

EQ: How can I describe the difference between the 3

types of passive transport?

How do nutrients and water get into cells?

cell membrane

Channel Protein

Cell

Membrane

Lipid

Outside of Cell

Inside of Cell

Marker Protein

ReceptorProtein

What is the cell

membrane made of? • Proteins and Lipids

lipid bilayer: two layers of lipids with proteins scattered through it

Substances are transported into and out of cells across the cell membrane in order to maintain

HOMEOSTASIS• Two Types of Transport:

–Active -- Passive

What is Passive Transport?

1. Requires no energy from cell.

2. Molecules move from high concentration to low concentration.

3. Molecules move with the concentration gradient.

Solution

Made up of

Solute % (salt, sugar, minerals)

Solvent %(Water)++

100 %

3 Types of Passive Transport

1. Diffusion

2. Osmosis

3. Facilitated Diffusion

1. DIFFUSION: when solutes move from high to low concentrations in

order to reach equilibrium

Diffusion through a cell membrane

2. OSMOSIS: when water moves from high to low concentration in order to reach equilibrium (a type of diffusion)

Cell Membrane

But wait!!!!! Can you foresee a problem with water molecules

passing through the lipid membrane?

Water molecules pass through special proteins called AQUAPORINS. They allow water molecules to pass through the membrane without coming in contact with the lipid’s hydrophobic tails.

Large molecules (glucose) aren’t able to fit through the lipid bilayer. How will they get

across?? I’m a Channel, I can help!

3. FACILITATED DIFFUSION: movement of large solutes from a

high concentration to a low concentration through CHANNEL

PROTEINS

Explain what is happening

CLOCK BUDDY TIME!!!!

With your 8:00 clock buddy, discuss the difference between the 3 types of passive transport:

1. diffusion

2. osmosis

3. facilitated diffusion

How is Active Transport different?

1. Active transport requires energy.

1. Solutes move from low concentration to high concentration

1. Molecules move against concentration gradient.

Cell Pumps: Active Transport

• The sodium-potassium pump is a classic example of a cell using active transport to move substances against the concentration gradient.

• It is vital in proper functioning of nerve cells.

Click on the diagram to see an animation of a potassium-sodium pump at work. On the website, scroll down to see the animation. It can be slowed down or stopped at will.

FormFood

Vacuole

LysosomesCome ToVacuole

Digestion

• Your white bloods cells also do this.• This is the ingestion of large particles

using energy.• Is it active or passive transport?

TrapFood

Amoeba

Amoeba engulfing a protist.

• White blood cells engulf bacteria and viruses in the same way.

• Is this active or passive transport?

Cellular Transport cont.

EQ: How can you decide if a solution is hypertonic, hypotonic, or isotonic?

Hypertonic Solution• Greater amount of solutes

(dissolved substances) in the solution compared to the cell.

70% Water30% Solutes

20% solute

Hypotonic Solution

• Fewer solutes (dissolved substances) in the solution as compared to the cell.

100% Water

0% solutes

20% solutes

Isotonic Solution• Same amount of solutes inside

and outside the cell.

80% Water20% Solutes

80% H2O

Remember the potato lab????

What type of solution was the saltwater solution?

The water?