Cellular Transport

How Your Cells Eat, Drink and be Merry!

EQ: Describe the structure of the cell membrane.

lipids

lipids

proteinsproteins

Which two major organic compounds were found in cell membranes?

How do nutrients and water get into cells?

cell membrane

Channel Protein

Cell

Membrane

Lipid

Outside of Cell

Inside of Cell

Marker Protein

ReceptorProtein

You eat and drink so that your cells can eat and drink!

• Cells must take in water and nutrients in order to maintain HOMEOSTASIS

Mmm…..

Oil (lipid) and water don’t mix – thank goodness!

• Water is essential for life!

• Every cell in your body is “swimming” in a solution with a very high water concentration.

• The lipid (oily) layer around cell maintains the cell as a unit, making sure it doesn’t dissolve away.

What is the cell

membrane made of? • Proteins and Lipids

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

Cell Membrane Proteins

Receptor: receive chemical messages

Channel: allow things in and out

Marker: identify the cell

Substances are TRANSPORTED into and out of cells across the cell membrane

• Two Types of Transport:–Passive–Active

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.

Diffusion: when substances move from high to low concentrations in

order to reach equilibrium

Diffusion through a cell membrane

Osmosis: when WATER moves from high to low concentration in order to reach equilibrium (a type of diffusion)

Cell Membrane

How are these big guys going

to get across? I’m a Channel, I can help!

Explain what is happening

There are 3 types of passive transport:

1. diffusion

2. osmosis

3. facilitated diffusion

What is the movement of water called?

Word from unit

Picture

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?