2. The Cell and its Environment: The processes behind the movement of substances in and out of cells

3. The Cell Membrane The cell membrane is like the walls of a space station. A.) It must protect its insides from the outside environment; B.) let in needed materials like food and water, and C.) get rid of wastes. A.) It must protect its insides from the outside environment; B.) let in needed materials like food and water, and C.) get rid of wastes. It is the cell membrane that controls what enters and leaves the cell. It is the cell membrane that controls what enters and leaves the cell. The cell membrane is like the walls of a space station. A.) It must protect its insides from the outside environment; B.) let in needed materials like food and water, and C.) get rid of wastes. A.) It must protect its insides from the outside environment; B.) let in needed materials like food and water, and C.) get rid of wastes. It is the cell membrane that controls what enters and leaves the cell. It is the cell membrane that controls what enters and leaves the cell.

4. The cell membrane is selectively permeable!!! / This means that some substances can pass through it and some can’t. / Substances can move into and out of a cell by one of three methods: Diffusion, Osmosis, or Active Transport / This means that some substances can pass through it and some can’t. / Substances can move into and out of a cell by one of three methods: Diffusion, Osmosis, or Active Transport

5. Passive Transport: Is the movement of substances through a cell membrane without using energy

6. Diffusion (passive transport) / Is the process by which molecules of a substance move from an area of high concentration to an area of low concentration / For example, if oxygen concentration is higher outside a cell than inside, the oxygen molecules will diffuse into the cell until the concentration inside is equal to the outside. / Is the process by which molecules of a substance move from an area of high concentration to an area of low concentration / For example, if oxygen concentration is higher outside a cell than inside, the oxygen molecules will diffuse into the cell until the concentration inside is equal to the outside.

7. Osmosis (passive transport) Osmosis (passive transport) / Is the diffusion of water through a selectively permeable membrane

8. Active Transport: is the movement of substances through the cell membrane using energy / Two main methods of active transport: / 1.) using transport proteins to pick up substances like salts or calcium outside the cell and carry them inside or carry them outside the cell the same way / 2.) Engulfing where the cell membrane surrounds a particle and forms a vacuole inside the cell / Two main methods of active transport: / 1.) using transport proteins to pick up substances like salts or calcium outside the cell and carry them inside or carry them outside the cell the same way / 2.) Engulfing where the cell membrane surrounds a particle and forms a vacuole inside the cell