Warm up The cell membrane is called phospholipid bilayer. – What is a phospholipid? – Which part of the phospholipid is hydrophobic? – Which part of the phospholipid is hydrophilic? – Define the term semi-permeable. – Quiz in 5 min.

Notes: Passive Transport Ch. 5 Pg

Cell Transport Molecules cross membrane in several ways – Some methods of transport require energy and some do not. – Depends molecules size, polarity, and concentration inside versus outside.

Cell Transport Small molecules and larger hydrophobic molecules move through bilayer easily. – e.g. O 2, CO 2, H 2 O

Cell Transport Ions, hydrophilic molecules, and large molecules do not move through the membrane on their own. – e.g. Na+, K+

Passive Transport Movement across the membrane WITHOUT the use of energy

Concentration Gradient Molecules have kinetic energy Concentration Gradient: difference between high and low concentration Molecules move “down” gradient without energy Equilibrium - when all molecules are evenly spread out Draw this!

Types of Passive Transport 1. Diffusion: Movement of molecules from high to low concentrations.

Types of Passive Transport 2. Facilitated Diffusion: Molecules too big to move across the membrane use carrier proteins Ex. Glucose

Types of Passive Transport 3. Osmosis: diffusion of water across membrane Water moves where there are more solutes. Solute: What gets dissolved. Solvent: What the Solute dissolves in. Solution: The mixture of the solute and the solvent.

Which way will the water move?

1. Hypotonic More solutes inside the cell, water moves in The cell swells Types of Tonicity Draw These Animal Cell Plant Cell

Hypertonic More solutes outside the cell, water moves out the cell The cell shrinks Animal Cell Plant Cell Draw these!

Isotonic Equal solutes inside and outside Water moves in and out at the same rate Cell stays the same Animal Cell Plant Cell Draw These! obQmk&index=2&list=PLexD8cl0p1- Z8r4WyQXQ6R6-Hg81nERSg