cell structure and function - the cell in its environment do now: how is the cell membrane shown...
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Cell Structure and Function - The Cell in Its Environment
Do Now: How is the cell membrane shown below like a colander?
Homework:
1.The cell in its environment worksheet
2.Mini Quiz Wednesday October 3rd.
2. Test on Wednesday, October 10th.
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Cell Structure and Function
•Cell membrane is selectively permeable- -some substances can pass through, while others cannot.
Permeable to: oxygen, water, carbon dioxide
Not permeable (impermeable) to: large molecules and salts
Cell Structure and Function
There are three methods by which substances move into and out of the cell:
diffusion, osmosis or active transport
Cell Structure and Function1) DIFFUSION: the process by which molecules move from an area of higher concentration to an area of lower concentration (high concentration--> low concentration)
Demonstration: air freshenerExample in text: page 41 unicellular organism in pond water..
Cell Structure and Function
2)OSMOSIS: diffusion of water molecules through a selectively permeable membrane, from high to low concentration.
Demo: Raisins in water
Example in text: Page 42 red blood cell
Cell Structure and Function - The Cell in Its Environment
Concentration of water is the same inside the cell as it is outside the cell
What happened to the cell? It stays the same size
Cell Structure and Function
Concentration of water is lower outside the cell.
What happened to the cell? It will shrink/shrivel
Cell Structure and Function
Concentration of water is higher outside the cell.
What happened to the cell? It will expand or even explode
Cell Structure and Function
3) ACTIVE TRANSPORT: the movement of materials through a cell membrane using energy (low high concentration)
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Cell Structure and Function
The movement through a cell membrane without using energy is called passive transport
The main difference between active transport and passive transport is:
For active transport the cell must use energy.
For passive transport the cell does not use energy.
Cell Structure and Function - The Cell in Its Environment
Active Transport takes materials from a low concentration to a high concentration.
There are transport proteins that help this happen and these transport proteins require energy to work.
Cell Structure and Function
What will be on the test?
Characteristics of Living Things
Needs of Living Things
The experiments: Is it a living thing lab, understand Redi and Pasteur concepts.
Cell Theory
Cells and their organelles
Cell Transport (diffusion, osmosis and active transport)