Download cell wall

Movement of molecules from an area where there are many to an area
where there are few
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
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
Animal cells and water movement
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