Diffusion and Osmosis Concepts

Mr. Anderson guides students through AP Biology Lab 1, focusing on diffusion and osmosis. The video explains diffusion as the movement of molecules from high to low concentration and osmosis as the movement of water across a semi-permeable membrane. The diffusion lab uses dialysis tubing to demonstrate molecule movement, while the osmosis lab involves placing potato cores in various sugar concentrations to observe mass changes. The video emphasizes understanding these processes through practical experiments.

What are the two main topics covered in the AP Biology Lab walkthrough?

• Diffusion and Osmosis

• Photosynthesis and Respiration

• Genetics and Evolution

• Cell Division and Growth

In the diffusion example with a jar, what happens to the sugar molecules over time?

• They remain on one side of the membrane.

• They move to create an unequal concentration.

• They migrate to achieve equal concentration on both sides.

• They dissolve completely in the water.

What is the primary difference between diffusion and osmosis?

• Diffusion requires energy, while osmosis does not.

• Diffusion involves only gases, while osmosis involves liquids.

• Diffusion occurs in solids, while osmosis occurs in gases.

• Diffusion is the movement of solutes, while osmosis is the movement of water.

In the osmosis example, why do sugar molecules not move across the semi-permeable membrane?

• They are too large to pass through the membrane.

• They dissolve in water before moving.

• They are repelled by the membrane.

• They are already in equilibrium.

What is the purpose of using dialysis tubing in the diffusion lab?

• To contain the starch solution

• To measure the rate of osmosis

• To act as a semi-permeable membrane

• To simulate a cell wall

What indicates the presence of starch in the diffusion lab setup?

• A red color change

• A green color change

• A blue color change

• A yellow color change

In the potato lab, what happens to the mass of potatoes in distilled water?

• The mass decreases

• The mass increases

• The mass fluctuates

• The mass remains the same

Why do potatoes lose mass in high sugar concentration solutions?

• Sugar enters the potato

• Water moves out of the potato

• Sugar leaves the potato

• Water moves into the potato

What is the significance of the point where the best fit line crosses the axis in the potato lab?

• It indicates the initial mass of the potato.

• It shows the final mass of the potato.

• It represents the molarity of the potato.

• It marks the time taken for osmosis.

What is the main goal of the potato lab experiment?

• To measure the rate of diffusion

• To test the permeability of potato skin

• To determine the sugar content in potatoes

• To observe osmosis and changes in potato mass