Exploring Diffusion and Osmosis in AP Biology

Ryan Cunningham introduces a lab on diffusion and osmosis from the AP Biology manual. The lab explores how solute concentration affects water movement through a selectively permeable membrane. The procedure involves using dialysis tubing and sucrose solutions to observe osmosis. Results show that higher solute concentrations increase the rate of osmosis. The video concludes with a discussion on the importance of diffusion in biological processes and potential errors in the experiment.

What is the main focus of the lab discussed in the video?

• Cell Division

• Genetic Mutations

• Diffusion and Osmosis

• Photosynthesis

Tags

NGSS.HS-LS1-4

NGSS.HS-LS1-5

What is diffusion?

• Formation of new cells

• Movement of water across a membrane

• Active transport of molecules

• Movement of a substance from high to low concentration

What is osmosis specifically concerned with?

• Movement of gases

• Movement of water

• Movement of solutes

• Movement of proteins

What is the first step in the lab procedure?

• Weighing the dialysis bags

• Tying knots in the tubing

• Soaking dialysis tubing in distilled water

• Filling the bags with sucrose solution

How long should the dialysis bags be left in distilled water for osmosis to occur?

• 40 minutes

• 10 minutes

• 20 minutes

• 30 minutes

What is done after removing the dialysis bags from the water?

• They are placed in a new solution

• They are left to air dry

• They are weighed immediately

• They are wiped dry

What was a potential error mentioned in the results analysis?

• Using tap water instead of distilled water

• Not soaking the tubing long enough

• Air bubbles in the dialysis bags

• Incorrect sucrose concentration

What does the increase in mass difference indicate in the experiment?

• No change in water movement

• More water entering the dialysis bag

• Less water entering the dialysis bag

• Decrease in solute concentration

How does the concentration of a solute affect the rate of osmosis?

• It reverses the direction of osmosis

• It increases the rate of osmosis

• It has no effect on osmosis

• It decreases the rate of osmosis

What is an example given to demonstrate diffusion?

• Melting ice

• Spraying perfume

• Burning a candle

• Boiling water