In an experiment, you create two groups of liposomes in a solution containing 0.1 M NaCl—one made from red blood cell membranes and the other from frog egg cell membranes. When the liposomes are placed in water, those with red blood cell membranes burst more rapidly than those made from egg membranes. What could explain these results? Select True or False for each of the following statements. a. T/F The red blood cell liposomes are more hypertonic relative to water than the frog egg liposomes. b. T/F The red blood cell liposomes are more hypotonic relative to water than the frog egg liposomes. c. T/F The red blood cell liposomes contain more aquaporins than the frog egg liposomes. d. T/F The frog egg liposomes contain ion channels, which are not present in the red blood cell liposomes.

Verified step by step guidance

1. Understand the terms: Hypertonic solutions have higher solute concentration than the cell, causing water to move out of the cell. Hypotonic solutions have lower solute concentration than the cell, causing water to move into the cell. Aquaporins facilitate water movement across cell membranes.
2. Analyze the experiment setup: Both types of liposomes are initially in a 0.1 M NaCl solution and then placed in water. The rapid bursting of red blood cell liposomes suggests a higher influx of water compared to the frog egg liposomes.
3. Evaluate statement a: If red blood cell liposomes are more hypertonic relative to water, they would have a higher solute concentration inside, causing water to move out, not burst. Thus, statement a is False.
4. Evaluate statement b: Since red blood cell liposomes burst more rapidly, it indicates they are more hypotonic relative to water, attracting more water into the liposomes. Thus, statement b is True.
5. Consider membrane protein differences: Aquaporins facilitate faster water movement. If red blood cell liposomes contain more aquaporins, it would explain the rapid water influx and bursting. Thus, statement c is likely True. Statement d is not directly related to the observed results and lacks evidence, so it is False.

Key Concepts

Osmosis and Tonicity

Osmosis is the movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. Tonicity refers to the relative concentration of solutes in a solution compared to another solution. A hypertonic solution has a higher solute concentration than the cell, causing water to leave the cell, while a hypotonic solution has a lower solute concentration, leading to water entering the cell. Understanding these concepts is crucial for explaining the behavior of liposomes in different solutions.

Membrane Composition and Permeability

The composition of cell membranes, including the types and amounts of lipids and proteins, affects their permeability to water and solutes. Red blood cell membranes are primarily composed of phospholipids and contain specific proteins that facilitate rapid water movement, while frog egg cell membranes may have different lipid compositions and protein channels. This difference in membrane structure can explain the varying rates of liposome bursting in response to osmotic pressure.

Aquaporins and Ion Channels

Aquaporins are specialized water channel proteins that facilitate the rapid transport of water across cell membranes, while ion channels allow specific ions to pass through the membrane. The presence of aquaporins in red blood cell membranes may contribute to their higher permeability to water compared to frog egg membranes, which may rely more on ion channels for maintaining osmotic balance. Understanding the role of these proteins is essential for interpreting the experimental results regarding liposome behavior.