Question

transport across the cell membrane
study the diagrams below. note the concentrations of the various solutions. the membrane is permeable to both water and glucose.

1. draw arrows indicating the net movement of each material. you can draw an arrow in google slides by going to insert >> line >> arrow. label each arrow by dragging and dropping the provided \glucose\ or \water\ text boxes.
2. is the solution in the beaker isotonic, hypertonic or hypotonic to the solution in the bag? label each solution under the picture using the provided text box.
3. are these substances moving across the membrane by active or passive transport? explain.
4. describe how the bag at a might change after a period of time has passed.
5. describe how the bag at b might change after a period of time has passed.

Explanation:

Step1: Determine net - movement of substances

Since the membrane is permeable to water and glucose, water will move from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration), and glucose will move from high to low concentration. For water, if the outside has more water percentage than inside, water moves in; if less, water moves out. For glucose, if outside has more glucose percentage than inside, glucose moves in; if less, glucose moves out.

Step2: Classify the solutions

An isotonic solution has equal solute concentrations inside and outside the cell (or bag in this case). A hypotonic solution has a lower solute concentration outside compared to inside, and a hypertonic solution has a higher solute concentration outside compared to inside. Compare the solute (glucose) concentrations in the beaker and the bag to classify the solutions.

Step3: Determine the type of transport

Passive transport does not require energy and occurs down a concentration gradient (from high to low concentration). Active transport requires energy and moves substances against a concentration gradient. Since water and glucose are moving down their concentration gradients here, it is passive transport.

Step4: Predict changes over time

In an isotonic situation, there is no net change in the size or shape of the bag over time. In a hypotonic situation, the bag will gain water and may swell. In a hypertonic situation, the bag will lose water and may shrink.

1. For the net - movement of substances: Draw arrows based on the concentration gradients of water and glucose as described above. Label the arrows as "Water" or "Glucose".
2. Compare the solute (glucose) concentrations in the beaker and the bag:

• If equal, it is isotonic.
• If beaker has lower glucose concentration, it is hypotonic.
• If beaker has higher glucose concentration, it is hypertonic.

1. The substances are moving by passive transport because they are moving down their concentration gradients (from high to low concentration) without the need for energy.
2. If the solution is isotonic (equal solute concentrations), the bag will maintain its shape and size. If hypotonic (lower solute in beaker), the bag will swell as water moves in. If hypertonic (higher solute in beaker), the bag will shrink as water moves out.

Answer:

1. Draw appropriate arrows and label them as "Water" or "Glucose" according to concentration gradients.
2. Classify the solutions as isotonic, hypotonic, or hypertonic based on glucose concentration comparison.
3. Passive transport.
4. Predict bag changes (maintain shape/size for isotonic, swell for hypotonic, shrink for hypertonic).