Your task is to investigate the effect of solute concentration on water potentia

Question

Your task is to investigate the effect of solute concentration on water potential as it relates to living plant tissues. Read the procedures in Part I and II and formulate a hypothesis that will be part of your lab report. In part I predict whether glucose or starch will move in or out of the dialysis tubing. In part II predict what will happen to the mass of each bag when they are placed in distilled water. 1. Fill a 200ml beaker with 200ml of distilled water. Add 4 drops of iodine solution into the beaker. 2. Obtain 1 strip of dialysis tubing, 10 - 12 cm long, and tie a knot in one end. 3. Pipette 5ml of a 30% glucose solution and 5mL of 10% starch solution into the tubing. Tie a knot at the end or use a clamp to keep the solutions from spilling. 4. Rinse the outside of the dialysis tubing and place the dialysis bag into the beaker that contains water/iodine solution. 5. After 30 minutes, record any observations. Remove the dialysis bag.

Explanation / Answer

Part I-

The experiment is based on selective permeability of a membrane that allows small molecules like glucose to pass and inhibits the passage of larger molecules like starch. Here, glucose due to its small size will move out of the dialysis bag and iodine will move in the dialysis bag turning the solution to blue black color, as bag's membrane will resist the starch passage due to its large size. The presence of glucose in the beaker's solution can be confirmed by Benedict's test..

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.