Question

Phospholipid vesicles prepared in 50 mM KCl were diluted in water. Based on this information, statements P and Q are made.
P: The diluted vesicles will develop membrane potential.
Q: There is a K⁺ concentration difference across the vesicular membrane.
Which one of the following options is correct?
 

• A. Both P and Q are true.
• B. P is true but Q is false.
• C. P is false but Q is true.
• D. Both P and Q are false.

Hint:

When vesicles are diluted in water, the concentration of ions such as Ksuperscript{+} changes, leading to a concentration gradient that can result in membrane potential development, depending on the permeability of the membrane to specific ions.

Answer 1

The Correct Option is C

- (P): The dilution of phospholipid vesicles in water does not automatically lead to the development of a membrane potential. The vesicles would have to have a pre-existing ion gradient (such as Na⁺ or K⁺) for a membrane potential to be generated. Dilution in water alone would likely cause the ions to diffuse and equalize, thus preventing membrane potential development. Therefore, statement (P) is false.

- (Q): If phospholipid vesicles are prepared in 50 mM KCl and then diluted in water, the dilution will cause a concentration gradient of K⁺ ions across the membrane. This concentration difference would lead to the development of a K⁺ gradient, which is true. Thus, statement (Q) is true.

Thus, the correct answer is (C).