Cell Transport

How molecules move in and out of a cell

Passive & Active Transport

• Passive Transport – requires no energyMoves molecules from high to low concentration

• Active Transport – requires energyMoves molecules from low to high concentration

Passive Transport

• http://programs.northlandcollege.edu/biology/biology1111/animations/passive1.swf

Passive Transport - 3 types

1. Simple Diffusion – molecules going from high to low concentration across a membrane

2. Facilitated Diffusion – molecules going from high to low concentration through a protein

3. Osmosis – diffusion of water

Active Transport

http://www.yellowtang.org/animations/endocytosis_exocytosis.swf

Passive Vs. Active Transport

• Active Transport– Requires Energy– Go from Low to

High Concentration– Use Proteins

• Passive Transport– No Energy– Go from High to

Low Concentration– May or may not

use proteins

Passive vs. Active Transport

Water water everywhere, but not a drop to drink!

The effects of osmosis on cells

Hypotonic Isotonic Hypertonic

Different solutions have different impacts on cells…

Hypertonic, Hypotonic, IsotonicWater always tries to balance itself out..so….

Hyper – high (more) Hypo – low (less)1. Hypertonic – more water inside the cell

Result – water flows out of cell2. Hypotonic - less water inside the cell

Result – water flows into the cell3. Isotonic – equal water inside/outside the cell

Result – water levels stay the same

Hypertonic, Hypotonic, Isotonic?

• What is it?

• What direction will the water move?

• What will happento the cell size?

Salt water

Hypertonic, Hypotonic, Isotonic?

• What is it?

• What direction will the water move?

• What will happento the cell size?

Pure water

Salt water

Hypertonic, Hypotonic, Isotonic?

• What is it?

• What direction will the water move?

• What will happento the cell size?

Pure water

Pure water

Think about this…….

• You have two identical pitchers side by side– one filled with exactly 2 quarts of water– the other filled with 2 quarts of Kool-aid

• Which has more water in it?

• WHY???