Cell Transport

Structure of the Cell Membrane Made of phospholipids and proteins Made of phospholipids and proteins Phospholipids look like a head with 2 tails. (look at the drawing on the board). Phospholipids look like a head with 2 tails. (look at the drawing on the board).

It is a double layered sheet called a lipid bilayer. It is a double layered sheet called a lipid bilayer. It is a barrier between the cell and its surroundings. It is a barrier between the cell and its surroundings.

Passive Transport Passive transport is movement of substances through the cell membrane without the use of energy. Passive transport is movement of substances through the cell membrane without the use of energy.

Types of Passive Transport 1. Diffusion: Movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached. 1. Diffusion: Movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached. Example: Spraying perfume in the room. Example: Spraying perfume in the room.

2. Osmosis: Movement of water from an area of high concentration to an area of low concentration until equilibrium is reached. 2. Osmosis: Movement of water from an area of high concentration to an area of low concentration until equilibrium is reached.

If there is more water inside a cell than outside a cell, the water will leave the cell. The cell will shrink. This means the cell is in a HYPERTONIC solution. If there is more water inside a cell than outside a cell, the water will leave the cell. The cell will shrink. This means the cell is in a HYPERTONIC solution.

If there is more water outside a cell than inside a cell, the water will flow into the cell. The cell will get bigger. This means the cell is in a HYPOTONIC solution. If there is more water outside a cell than inside a cell, the water will flow into the cell. The cell will get bigger. This means the cell is in a HYPOTONIC solution.

If there is the same amount of water inside the cell as there is outside the cell, water will flow in and out at an equal rate. The solution is said to be ISOTONIC. If there is the same amount of water inside the cell as there is outside the cell, water will flow in and out at an equal rate. The solution is said to be ISOTONIC.

3. Facilitated diffusion: Movement of particles across the membrane through certain proteins that act as channels or tunnels. If these channels did not help, the molecules could not get through. 3. Facilitated diffusion: Movement of particles across the membrane through certain proteins that act as channels or tunnels. If these channels did not help, the molecules could not get through.

Active Transport Movement of particles through the cell membrane USING ENERGY. Movement of particles through the cell membrane USING ENERGY.

Types of Active Transport 1. Endocytosis: Process of taking material into the cell by the use of infoldings or pockets in the cell membrane. 1. Endocytosis: Process of taking material into the cell by the use of infoldings or pockets in the cell membrane.

2. Exocytosis: Process of of removing large molecules from the cell. 2. Exocytosis: Process of of removing large molecules from the cell.