Okay, so in the Lab Assignment that I'm currently working on in AP Biology, there is a question that says:
- What results would you expect if a dialysis bag were filled with glucose and iodine and then placed into a beaker of starch and water?
Its a multiple choice question (which you think would make it easier but in all reality, it just confused me more.
The options were:
*A.)There would be a movement of glucose into the bag, and the water outside of the bag would turn purple.
*B.)There would be movement of glucose out of the bag, and the water outside of the bag would turn purple.
*C.)There would be a movement of starch into the bag, and the inside of the bag would turn purple.
*D.)There would be a movement of starch into the bag and the outside of the bag would turn purple.
First though was that water would move into the bag to an area of lower water potential but then I realized that there is no water in the bag to begin with and it isnt an option. I went over the lab several times and I can't seem to find the answer, the lab didn't come from my textbook so its not in there, and I don't know how to research it on the web because its not a definition or anything - Its lab results. I know that this isn't a place to come for straight answers on homework so I'm not asking for that. Just hoping maybe someone could shine a little light on this and point me in the right direction since at the moment, the information that I have (nothing) is getting me absolutely nowhere. Any help is highly appreciated. Thanks in advance.
Multiple Post. Please see later post.
Sra
I can definitely help you with this question! Understanding the principles of diffusion and osmosis will allow you to determine the correct answer. Here's how to approach it:
1. Review the concepts of diffusion and osmosis:
- Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. It occurs because particles naturally tend to distribute themselves evenly.
- Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
2. Analyze the experimental setup:
- In this case, the dialysis bag acts as a selectively permeable membrane that allows smaller molecules like glucose and iodine to pass through, but not larger molecules like starch.
- The beaker contains starch and water, indicating that the solute concentration is highest outside the dialysis bag.
3. Predict the movement of molecules and the color change:
- Glucose is a smaller molecule than starch, so it can diffuse through the dialysis bag. Therefore, glucose would move out of the bag.
- Iodine is also a small molecule that can pass through the dialysis bag. It can interact with starch to produce a blue-black color.
- The movement of glucose out of the bag and the interaction of iodine with starch outside the bag would result in a specific outcome.
4. Evaluate the answer options:
- Option A suggests that glucose moves into the bag and the water outside turns purple. This goes against the principles of diffusion and osmosis since glucose would move out of the bag.
- Option B correctly states that there would be movement of glucose out of the bag but incorrectly mentions the water turning purple, which should actually occur due to iodine reacting with starch.
- Option C suggests a movement of starch into the bag, which is not possible because the dialysis membrane does not allow starch to pass through.
- Option D correctly states that there would be movement of starch into the bag, which is not possible, and mentions the outside of the bag turning purple, which is the expected outcome due to the interaction of iodine with starch.
Based on this analysis, option D is the most accurate answer: There would be a movement of starch into the bag, and the outside of the bag would turn purple.
By understanding the principles of diffusion and osmosis and applying them to the experimental setup, you can deduce the expected outcome. Good luck with your lab assignment!