Download - Moving Cellular Materials
UNIT 3 – Lesson 5 Notes
Cell Membrane
Passive Transport
The movement of substances through the cell membrane without the input of energy.
1.Diffusion2.Osmosis3.Facilitated Diffusion
NO ENERGY required!
Diffusion
The random movement of molecules from a high concentration to a low concentration.
But what does having a high concentration mean?
CLASS DEMO
Diffusion Molecules of a substance will continue
to move until the relative number of these molecules is equal in both areas. This is called equilibrium.
Example: Oxygen from lungs diffuses into blood.
Simple Demo
Osmosis The diffusion of water molecules into or
out of the cell.
Water moves from an area of higher water molecule concentration to an area of lower water molecule concentration.
Humm…sounds just like diffusion – except it’s with
water!
Osmosis This movement will occur across a
membrane.
“Salt Sucks” – salt sucks water out of things.Cell
Exposed to Pure Water
Normal Cell Cell Exposed to Salt
Osmosis in Strawberries
Facilitated Diffusion The diffusion of molecules across a
membrane with the help of transport proteins.
Allows large molecules to cross the membrane.
Facilitated Diffusion
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Diffusion will continue until an equilibrium is reached!
Facilitated Diffusion
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Diffusion will continue until an equilibrium is reached!
Active Transport An input of energy is required to move
materials through a cell membrane.
A transport protein binds with the needed particle and cellular energy is used to move it through the cell membrane.
Active Transport Molecules are moved against a
concentration gradient. They move from areas of low concentration to areas of high concentration. concentration.
That is why energy is required.
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Active Transport
Cell Membrane
Transport Proteins
Cytoplasm
Outside of Cell
Molecules move from low to high concentrations!
Endocytosis The process of taking substances into a
cell by surrounding it with the cell membrane.
The cell membrane folds in on itself, enclosing the item in a sphere called a vesicle. The sphere pinches off, and the resulting vesicle enters the cytoplasm.
Exocytosis
The process of getting rid of substances.
The membrane of the vesicle fuses with the cell’s membrane and the contents are released.
Inside of Cell Outside of Cell