Download Lab:!Passive!&!Active!Transport! and more Study notes Cell Biology in PDF only on Docsity! Lab:!Passive!&!Active!Transport! The cell membrane is semi-permeable. This means some materials are allowed through and some are not. The size, shape, and charge of the molecules determines whether they can pass or not. Passive Transport • The movement of materials through a membrane without energy • Diffusion: the movement of materials from high concentration to low concentration • Osmosis: the diffusion of water through a membrane Active Transport • The process of using energy to move materials through a membrane • Some materials, like sugar or salt, are too big to flow through the membrane • Instead, the cell needs energy to move the molecule through a protein. o What type of energy? ATP! • Cells in our kidneys filter & remove salt from your blood through active transport. Endocytosis • Occurs when a large bit of material is captured with a pocket in the membrane • The pocket breaks off & forms a package that moves into the cell • Requires energy • Essential nutrients, like iron, are absorbed into cells this way 1. 2. 3. Exocytosis • Occurs when a large bit of material needs to be removed from a cell • A package of the materials travels through the cell to the membrane, joins it, and is expelled • Requires energy • Cells use this to flush out waste such as hormones 1. 2. 3. Part 1: Plastic Bag Membrane Materials: plastic bags, rubber bands, 2 beakers, cornstarch, iodine, water, 50 ml graduated cylinder, teaspoon Procedures 1. Label two clean glass 200ml beakers 1 & 2. 2. Pour approximately 100 mL of water into each beaker. 3. Add 1 teaspoon of cornstarch into beaker 1. Stir until mostly or fully mixed. 4. Add 10 drops of iodine into beaker 2. (careful, iodine will stain clothes) 5. Use the graduated cylinder to pour 30 mL of water into a plastic bag. Add 10 drops of iodine to the bag. Rubber band to seal the bag. Gently place the bag into beaker 1. Record/draw the initial color below. 6. Use the graduated cylinder to pour 30 mL of water into the other plastic bag. Add 1 tsp of cornstarch to the bag and mix well. Rubber band to seal the bag. Gently place the bag into beaker 2. Record observations. 7. Let the bags sit for 10-15 minutes. (Move on to part two while you wait). 8. After 15 minutes, record your observations below. 9. Let the bags sit for 24-48 hours & record observations again. Observations 1. Iodine Bag in Cornstarch Water 2. Cornstarch Bag in Iodine Water Initial Observations After 15 Minutes After 24-48 hours
