Download Bell Work: 1/5/10

Looking at Cells
Bell Work:9/17/14
 Complete the Warm up sheet- Use your
notes or Science book.
Objectives
 Explain how materials move through
simple diffusion. (SPI 0707.1.5)
 Diffusion/Osmosis Demo & Notes
Challenge Question?
 What cell organelle allows things to move
in and out of the cell?
 What things are allowed in and out of the
cell?
Discuss the questions with your Elbow
Partner.
Teacher Demo
• Soap bubbles have
properties, such as
flexibility, that are similar
to cell membranes.
• Components of soap film
and of cell membranes
move around freely
because they are made of
proteins and lipids (fats).
What is Diffusion?
 The movement of particles from regions
or areas of _________
concentration
high
(crowded) to areas of ________
low
concentration (less crowded) is called
____________.
diffusion
 Teacher Demo:
 The dye moved from an area of high
concentration and spread to the area of
low concentration.
 Ex: when oxygen diffuses into the cell
and carbon dioxide diffuses out.
Diffusion of Water
 Diffusion also happens with and between
living cells.
 The cells of organisms are surrounded by
and filled with fluids that are made mostly of
________.
water
 The diffusion of water through a
_____________
semipermeable (partially allows things
through) membrane is so important that it
has been given a special name__________.
osmosis
Question...Elbow Partner
 In diffusion and osmosis, why do the
particles move from areas that are
more crowded to areas that are less
crowded?
 For a cell to survive, the amount of
molecules need to be the same on both
sides of the cell membrane. If the cell
does not pump out all of its extras to
even things out, this could be very bad.
The cell can swell up and explode.
Moving Small Particles
 In a cell, the movement of particles across a cell
membrane _________
without the use of energy by the cell is
called __________
passive ___________.
transport
 During passive transport, particles move from an area
of _______
high concentration to an area of _______
low
concentration.
 Examples:__________
Diffusion & __________
Osmosis
activethat requires
transport
 A process of transporting particles
the
cell to use energy is called ________ ____________.
low
high usually involves the movement of
 Active transport
particles from an area of _______ concentration to an
area of _______ concentration.
Moving Large Particles
 The active transport by which a cell surrounds a large
particle, such as a large _________,
protein and encloses the
particle in a vesicle to bring the particle into the cell is
called _______________.
endocytosis
 Vesicles are _____
sacs formed from pieces of cell
membrane.
 Ex: when iron diffuses into the cell using active
transport because the iron molecules are too large.
 When large particles, such as ________,
wastes leave the
cell, the cell uses an active transport called
______________.
exocytosis
 During exocytosis, a vesicle forms around the large
particle, carries the particle to the cell membrane,
fuses with the cell membrane, and releases the
particle outside of the cell.
What do you know?
(Einstein Award Opportunity)
Describe how each of the following materials
would get through the cell membrane and
into a cell:
1. Pure water (osmosis)
2. Sugar entering a cell that already contains a
high concentration of particles (active transport)
3. Sugar entering a cell that has a low
concentration of particles (passive transport)
4. A protein (endocytosis)