You have prepared lipid vesicles (spherical lipid bilayers) that contain Na^+ -K

Question

You have prepared lipid vesicles (spherical lipid bilayers) that contain Na^+ -K^+ pumps as the sole membrane protein. All of the Na^+ -K^+ pumps are oriented in such a way that the portion of the molecule that normally faces the cytosol is in the inside of the vesicle and the portion of the molecule that normally faces the extracellular space on the outside of the vesicle. Assume that each pump transports one Na^+ ion in one direction and one K^+ ion in the other direction during each pumping cycle (see Figure Q12-15 for how the Na^+ -K^+ pump normally functions in the plasma membrane). Predict what would happen in each of the following conditions: The solutions inside and outside the vesicles contain both Na^+ and K^+ ions but no ATP. The solution outside the vesicles contains both Na^+ and K^+ ions;the solution inside contains both Na^+ and K^+ ions and ATP. The solution outside contains Na^+;the solution inside contains Na^+ and ATP.

Explanation / Answer

A. Na-K pump is a energy required process ATP is needed to open the channel. Due to No ATP present in the solution Na-K pump not able to operate or function.

B. Due to ATP present inside the cells Na-K pump will ON. one Na+ ions goes outside and one K+ ions comes inside of the cells until all the Na+ goes out or all ATP will be used in the cell..

C. Due to no K+ ions present in the solution the pump is not able to operate properly. Because for conformational change dephosphorylation must be occur for that K+ ions required. After dephosphorylation K+ ions goes out. For next cycle ATP has to hydrolysed and make Na+ ions binds to the pump. It is a cyclic process.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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