Warm-UP page 27

•  Define Passive Transport.

•  Provide an example.

•  Agenda: •  Osmosis Notes •  Starch and Iodine Lab •  Egg Lab •  Work on Study Guide

The Cell Membrane and

Types of Transport

Osmosis a type of passive transport

•  Osmosis is the diffusion of water molecules through a selectively permeable membrane

•  In osmosis, the water moves from an area of greater concentration to an area of lesser concentration

•  Because the water is moving down a concentration gradient, NO ENERGY is needed

3 types of Osmosis Solutions

•  Hypertonic Solution •  In a hypertonic solution there is a

GREATER concentration of water INSIDE of the cell AND LESS water concentration OUTSIDE of the cell •  So, the water moves OUT of the cell

until the concentrations of water are equal

•  A cell placed in a hypertonic solution will get smaller!

3 types of Osmosis Solutions •  Hypotonic Solution •  In a hypotonic solution there is a

GREATER concentration of water OUTSIDE of the cell AND LESS water concentration INSIDE of the cell •  So, the water moves INTO the cell

until the concentrations of water are equal

•  A cell placed in a hypotonic solution will get bigger!

3 types of Osmosis Solutions

•  Isotonic Solution •  In an isotonic solution there is an EQUAL concentration

of water OUTSIDE AND INSIDE the cell •  So, the water moves IN BOTH DIRECTIONS, so the

water concentrations stay equal. •  A cell placed in an isotonic solution will stay the same

size!

Osmosis Solutions

Starch and Iodine Lab

•  Careful with Iodine! Will stain clothing and skin

Egg Lab

•  GENTLY!!!!! Do not break your egg