1. Section 7-3 cont. Active Transport

2. Requires energy from the cell Requires energy from the cell Moves from low to high concentration Moves from low to high concentration

3. 1. Carrier Proteins Each type of carrier protein has a shape that fits a specific molecule. Each type of carrier protein has a shape that fits a specific molecule. After the molecule binds to the protein, chemical energy allows the cell to change the shape of the carrier protein. After the molecule binds to the protein, chemical energy allows the cell to change the shape of the carrier protein. The particle is then released on the other side of the membrane. The particle is then released on the other side of the membrane. After the particle is released, the original shape comes back. After the particle is released, the original shape comes back.

4. Carrier Proteins cont.

5. Active Transport cont. 2. Endocytosis – process by which a cell surrounds and takes in material from its environment. 2. Endocytosis – process by which a cell surrounds and takes in material from its environment. Does not pass through the membrane. Does not pass through the membrane. It is engulfed and enclosed by a portion of the cell’s plasma membrane. It is engulfed and enclosed by a portion of the cell’s plasma membrane.

6. Active Transport cont. 3. Exocytosis – the expulsion or secretion of materials from a cell 3. Exocytosis – the expulsion or secretion of materials from a cell Used to get rid of waste and secrete hormones. Used to get rid of waste and secrete hormones.