Lab: Passive & Active Transport

NAme: Date: 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 determine 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 and remove salt from our blood through active transport

Endocytosis

● Occurs when a large bit of material is captured with a pocket in the cell membrane ● The pocket breaks off and forms a package that moves into the cell ● Requires energy ● Essential nutrients, like iron, are absorbed into cells this way

Pinocytosis: ______Phagocytosis: ______Exocytosis

● Occurs when a large bit of material needs to be removed from a cell ● A package of the materials travels through the cell membrane, joins it, and is expelled ● Requires energy ● Cells use this to flush out waste such as hormones Throughout this lab, you will analyze how materials travel through the cell membrane. Some important terms to understand are isotonic, hypotonic, and hypertonic. If the molecules outside the cell are lower than the concentration inside the cell, the solution is said to be hypotonic. In this process, water diffuses into the cell until equilibrium is reached. If the molecules outside the cell are higher than the concentration inside the cell, the solution is said to be hypertonic. In this process, water diffuses out of the cell until equilibrium is reached. If the molecules outside and inside the cell are equal, the solution is said to be isotonic. In this process, water diffuses into and out of the cell at equal rates, causing no net movement of water.

Iso means ______hypo means ______hyper means ______

Part 1: Egg Shell Membrane

Materials: raw egg, 400 mL beaker, balance, vinegar, corn syrup

Hypothesis: What will happen to an egg after soaking for 24 hours in. . . .

1. Vinegar? ______2. Corn Syrup? ______3. Tap water? ______

Day 1: Wednesday

1. Obtain and find the mass of a raw egg. Record in the table below. 2. Carefully place the egg in a 400ml beaker labeled with your name. 3. Add vinegar to the beaker until the egg is fully covered. Record your observations. 4. Cover with saran wrap and leave overnight.

Day 2: Thursday

5. Very carefully take the egg out of the vinegar and place it on the balance. Record the mass. 6. What else happened to the egg? Record any other observations. 7. Clean the beaker with soap and water, then gently place the egg back in the beaker. 8. Add corn syrup to the beaker until the egg is fully covered. Record your observations. 9. Cover with saran wrap and leave overnight.

Day 3: Friday

10. Repeat steps 5-7. 11. Add distilled water to the beaker until the egg is fully covered. Record initial observations. 12. Cover with saran wrap and leave overnight.

Day 4: Monday

13. Repeat steps 5 and 6. Throw away the egg. Part 2: Conclusion- Answer thoughtfully & thoroughly, attach extra paper if necessary, use data to support your answer.

1. When the egg was placed in the water, in which direction did the water molecules move?

2. On what evidence do you base this?

3. How do you explain the amount of liquid remaining when the egg was removed from the syrup?

4. When the egg was placed in the water, in which direction did the water move?

5. Why did the water molecules travel better inside the cell than the syrup molecules?

6. What was the purpose of placing the egg in the vinegar?