Diffusion & Osmosis
What is Diffusion?
The movement of particles from regions or areas of _________ concentration
(crowded) to areas of ________ concentration (less crowded) is called
Look at Figure 1 on pg. 78!
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 ________.
The diffusion of water through a ____________________ (partially allows things through) membrane is so important that it has been given a special name- __________.
Look at Figure 2 on pg. 79!
Moving Small Particles
In a cell, the movement of particles across a cell membrane _________ the use of energy by the cell is called __________ ___________.
During passive transport, particles move from an area of _______ concentration to an area of _______ concentration.
Examples:__________ & __________
A process of transporting particles that requires the cell to use energy is called ________ ____________.
Active transport usually involves the movement of particles from an area of
_______ concentration to an area of _______ concentration.
Ex. when iron diffuses into the cell using active transport because the iron molecules are too large.
Moving Large Particles
The active transport by which a cell surrounds a large particle, such as a large
_________, and encloses the particle in a vesicle to bring the particle into the cell is called _______________.
Vesicles are _____ formed from pieces of cell membrane.
When large particles, such as ________, leave the cell, the cell uses an active transport called ______________.
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.