Chapter 4 Exchange with the Environment Cell Energy The Cell Cycle

Essential question on cells: This chapter answers the

diffusionosmosisActive transport endocytosisexocytosisPassive transport Fluency Chart

Section 1 Exchange with the Environment

Movement of “Tiny” particles: Called Diffusion. The movement of particles from high concentration to an area of low concentration. Happens in gases, liquids, and solids Ex. Of tiny particles: O 2, H 2 0, CO 2

Gases diffuse in other gases…

Liquids diffuse into other liquids…

Solids diffuse into other solids…

Particles always move… Brainpop

It’s about the membrane silly! The membrane is made of phospholipid molecules. They have two parts to them. One is the two hydrophobic tails. The other is the hydrophilic head. Diagram of a membrane:

Plant and Animal Cell Rap

A special diffusion of H 2 0 across a cell membrane Water moves from high concentration to low concentration OSMOSIS:

Osmosis…

Diagram of how osmosis works: Extreme osmosis: Tap the cell

A comparison…… diffusion osmosis both

Movement of “small ” particles: Examples are sugars or amino acids These can’t pass through the “phospholipid molecules” in the cell membrane Need special protein channels to get in. TWO types of movement:

1) Passive transport Particle diffuses through protein channels from an area of high concentration to an area of low concentration Does not require any energy

2) Active Transport Movement of particles through proteins against the normal direction of diffusion. (low to high concentration) Requires the cell’s ATP (needs energy) protein channel

Diagram of active transport:

Passive and Active Transport Passive Active Both

CELL MEMBRANE: Tap the pic.

Moving Large Particles: Two ways : 1) Bringing things in… Endocytosis 2) Getting things out of the cell… Exocytosis videovideo

Animation of exocytosis:

Concept map…