PASSIVE TRANSPORT

CHAPTER 5

PGS 97-102

PASSIVE TRANSPORT

•Movement across the cell membrane without energy.

REVIEW: What characteristics does the cell membrane have?

• Selectively permeable

• Get rid of waste

• Interact with the environment

I. CONCENTRATION GRADIENT

•Molecules have kinetic energy (they

move)

•Concentration Gradient: difference

between high and low concentration

•Molecules move “down” gradient

•Equilibrium: when all molecules are

evenly spread out

DRAW THIS!

II. TYPES OF PASSIVE TRANSPORT

• Diffusion: movement across the cell membrane without energy

II. TYPES OF PASSIVE TRANSPORT

• Osmosis: special diffusion of water across membrane

• Water moves where there are more solutes (solids)

III. TYPES OF TONICITY

1. Hypotonic

• More solutes inside the cell, water moves in

• The cell swells

Draw one of theseAnimal Cell Plant Cell

III. TYPES OF TONICITY

2. Hypertonic

• More solutes outside the cell, water moves out

• The cell shrinks

Draw one of theseAnimal Cell Plant Cell

III. TYPES OF TONICITY

3. Isotonic

• Equal solutes inside and outside

• Cell stays the same, equal movement of water in and

out of cell

Draw one of theseAnimal Cell Plant Cell

REAL LIFE APPLICATION

IV. FACILITATED DIFFUSION

• Molecules too big to move across the membrane use carrier proteins

• Ex. Glucose