Diffusion and Indicators in Cells

Dr. Wifer guides viewers through a virtual lab on diffusion through a membrane. The video covers the use of indicators like Benedict's solution for glucose and iodine for starch. It explains how these indicators work and demonstrates their application. The lab uses a dialysis membrane to simulate cell diffusion, showing how different substances move across the membrane. The results highlight the semi-permeable nature of the membrane, with glucose and iodine diffusing but not starch. The video concludes with an analysis of the experiment's outcomes.

What is the primary purpose of using indicators in this lab?

• To determine the pH level of solutions

• To observe physical changes in the membrane

• To test for the presence of specific substances

• To measure temperature changes

What color does Benedict's solution turn in the presence of glucose after heating?

• Yellow

• Blue

• Green

• Red

Which solution is used to test for the presence of starch?

• Glucose solution

• Benedict's solution

• Iodine solution

• Water

What color does iodine solution turn in the presence of starch?

• Amber

• Red

• Blue

• Purple or black

What is the function of the dialysis membrane in the experiment?

• To act as a control

• To simulate a cell membrane

• To measure temperature changes

• To test for pH levels

What solutions are placed inside the artificial cell made from the dialysis membrane?

• Only glucose solution

• Only starch solution

• Half glucose solution and half starch solution

• Only water

What happens to the iodine solution outside the artificial cell over time?

• It changes color to purple or black

• It remains the same

• It evaporates

• It turns blue

Did the starch inside the artificial cell diffuse to the outside solution?

• Only in the presence of heat

• Partially

• No, not at all

• Yes, completely

What evidence shows that glucose diffused from inside the artificial cell to the outside?

• The outside solution turned red after heating with Benedict's solution

• The outside solution turned purple

• The outside solution bubbled

• The outside solution remained blue

Why didn't starch diffuse through the dialysis membrane?

• It was not mixed properly

• It was too small

• It was too large

• It was not heated