1. Transport The movement of molecules and ions across a membrane

2. Molecules in motion At all times molecules and ions are moving into and out of your cells. The nutrients and oxygen your cells need for respiration move in, and the waste products move out. This activity is regulated by the cell membrane.

3. Transport As we learned earlier, transport (the intake and distribution of materials throughout an organism) is one of the life processes. All molecules are not transported the same. Some types of transport require energy and others do not. Sometimes molecules need a little help getting from one side of the cell membrane to the other.

4. Types of transport I.Passive transport II.Active transport III.Endocytosis (Phagocytosis and Pinocytosis) IV.Cyclosis

5. Passive transport In passive transport there are two things that you must remember. 1. There is no energy required. 2. Molecules move from areas of high concentration to low concentration. –Small molecules easily pass through the cell membrane while larger ones need help. –With ions, the charge of the particles can also determine if they can diffuse across a cell membrane.

6. Simple Diffusion Small molecules, such as dissolved oxygen, carbon dioxide and glucose pass through the cell membrane. They always move with the concentration gradient, from high to low. No energy is required.

7. Facilitated diffusion Sometimes molecules are too big to pass through the cell membrane on their own. These larger molecules require the help of carrier proteins. Carrier or channel forming proteins are embedded in the cell membrane. As with simple diffusion, no energy is required, and molecules and ions move with the concentration gradient.

8. Osmosis Osmosis refers to the passive transport of water molecules across a cell membrane. As with the other times of passive transport the water molecules move from high concentration to low concentration. No energy is required for Osmosis.

9. Diffusion summation No energy Molecules move with the gradient Continues until equilibrium is reached. This means that the concentration of molecules are the same on both sides of the membrane.

10. Passive transport video http://www.youtube.com/watch?v=JShw XBWGMyY

11. Active transport Active transport is fundamentally different from passive transport. In active transport, molecules move against the concentration gradient, which means they move from areas of low concentration to high concentration. It also requires energy.

12. Endocytosis Endocytosis simply means the ingestion of solids or liquids into a cell. Phagocytosis is the process by which solids are taken into a cell. An amoeba eats paramecium by the process of phagocytosis. Pinocytosis is the process by which liquids are taken into a cell. Both phagocytosis and pinocytosis lead to the production of vacuoles. The reverse process, of materials leaving a cell is called exocytosis.

13. Passive v. active transport http://www.youtube.com/watch?v=1ZFq OvxXg9M&feature=relatedhttp://www.youtube.com/watch?v=1ZFq OvxXg9M&feature=related

14. Cyclosis Cyclosis is the swirling motion of the cytoplasm that helps to distribute materials throughout a cell. Cyclosis does not directly require any energy. The normal motion of the cell or organism helps to create this motion.