Download cell wall

Selectively Permeable Membrane- [like a strainer]
- contains different size openings called pores
- only materials smaller than openings pass through
Diffusion- Movement of molecules from an area where
there are many to an area where there are few
Examples: food coloring in water, spraying air freshener
Simple Rule:
CONTINUES UNTIL …….
Equilibrium/Homeostasis- molecules are equally distributed in an
area
Osmosis- movement of WATER molecules from an area
where there are many to an area where there are few
Which way will molecules move?
What process is it?
10% Water
100%
Water
Time
Osmosis
High sugar
Low
Sugar
Time
Diffusion
Osmosis can effect plant
and animal cells differently
 Can
you think of which cell
organelle that a plant has which
an animal cell does not, that may
have something to do with this?

The Cell Wall!!
Plant Cells
Fresh Water
Salt Water
Cell Membrane
Plasmolysis- cell membrane shrinking away from
cell wall, due to water exiting cell
Why?
Salt is a substance that will draw water in its direction. This
is why you feel thirsty when you eat something salty.
Simple Rule:
Plant Cells
HYPO = less
TONIC = solution
HYPOTONIC CELL
100% H2O
HYPER= more
TONIC = solution
HYPERTONIC CELL
90% H2O
10% NaCl
97% H2O
Water rushes into cell, keeps cell
rigid
97% H2O
Water moves out of cell,
Cell membrane pulls away
from cell wall PLASMOLYSIS
HYPOTONIC CELL
100% H2O
90% H2O
- Water rushes into cell
- Cell swells and may burst due to
lack of cell wall
HYPERTONIC CELL
95% H2O
100% H2O
- Water rushes out of cell
- Cell shrinks due to lack of cell
wall
ISOTONIC CELL
97% H2O
97% H2O
- Cell does not change, water equal
inside and out
Equilibrium/Homeostasis
ISO = same
TONIC = solution
Active Transport –
requires energy
Endocytosis- process used by cells to transport
large materials [proteins] INTO cell
Greek terms : ENDO = inside
CYTOSIS = relates to cell
Exocytosis- process used by cell to move wastes
or other materials OUT of cell
Greek terms : EXO = outside
CYTOSIS = relates to cell
What do you know?






What are the 2 general types of cell transport
and what is the difference between them?
How does a selectively permeable membrane
work?
What is diffusion?
What is osmosis and how is it different in plant
and animal cells?
What is the difference between hypertonic,
hypotonic, and isotonic cells?
What are the 2 types of active transport and how
do they work?