Transcript Diffusionosmosis07 - McCarthy`s Cool Science

Assignment #
Diffusion and Osmosis
Mrs. McCarthy
Biology
April 11, 2016
I. The Cell
A. In order to live, a cell must take in
nutrients and water and eliminate
wastes
B. Parts of the cell involved in diffusion
and osmosis:
1. Cell membrane – a semipermeable
membrane that allows some small
molecules through, but blocks others.
Water is able to pass through freely.
The Cell Membrane
I. The Cell
2. Cytoplasm – the jelly like substance
in the cell that is composed of mainly
water and dissolved solutes.
II. The movement of
Substances Into and Out of Cells
A. Diffusion is the movement of molecules
from an area of greater concentration to
an area of lesser concentration
1. Diffusion stops when equilibrium
(balance) is reached
Diffusion causes the molecules to
move from area A to area B
Diffusion causes the molecules to
move from an area of high
concentration to an area of low
concentration
II. The movement of
Substances Into and Out of Cells
B. Osmosis is the diffusion of water across
the cell membrane
1. The water will move from an area of
low solute to an area of high solute
until equilibrium is reached. (The
water wants to evenly dilute the
solute)
In osmosis, the water will move
towards the solute to dilute it
evenly.
Osmosis
III. Types of solutions
A. Hypertonic – the concentration of
solutes outside the cell is greater than it
is inside.
1. Water will move outside the cell to
dilute the higher concentration of
solutes
2. The cell will shrink
Hypertonic Solution
IV. Models of Different
Solutions (turn to the back)
A. A cell in a HYPERTONIC SOLUTION
X = NaCl (salt)
O = H2O
X
O X
X O
X O O O
X
X
X
X
X O
X
X
X
XO
X
O
O
O
X
X
III. Types of solutions
B. HypOtonic – the concentration of
solutes inside the cell is greater than it is
outside
1. Water will move inside the cell to
dilute the higher concentration of
solutes
2. The cell will SWELL (unless the
water is pumped out by a contractile
vacuole)
HypOtonic solution
IV. Models of Different
Solutions (turn to the back)
A. A cell in a HYPOTONIC SOLUTION
X = NaCl (salt)
O = H2O
O
O
X
O
O
X
X
O
OXX
O
O
O
O
X
X
O
X O
X
O
XO
O
O
The contractile vacuole in single
celled organisms pumps out excess
water so the cell does not burst
III. Types of solutions
C. Isotonic – the concentration of solutes
inside and outside the cell is the same
1. Water will not move
2. The cell will stay the same
Isotonic solution
IV. Models of Different
Solutions (turn to the back)
A. A cell in a ISOTONIC SOLUTION
X = NaCl (salt)
O = H2O
X O
O
O
X
O
X
O
X O
O
X
O X
X
X
O
X
O X
Journal Entry #
1. Explain the difference between osmosis
and diffusion.
2. Explain this cartoon using the terms
osmosis, hypertonic, and diffusion.
Classwork
Complete the Diffusion and Osmosis
practice worksheet. Be sure to read all
directions very carefully.