To study the mechanism of SERCA, you prepare membrane vesicles containing this protein oriented such that its ATP binding site is on the outer surface of the vesicle. To measure pump activity, you use an assay that detects the formation of inorganic phosphate in the medium. When you add calcium and ATP to the medium, you observe phosphate production for only a short period of time. Only after the addition of calcimycin , a molecule that makes membranes selectively permeable to calcium, do you observe sustained phosphate production. Explain.

To study the mechanism of SERCA, you prepare membrane vesicles containing this protein oriented such that its ATP binding site is on the outer surface of the vesicle. To measure pump activity, you use an assay that detects the formation of inorganic phosphate in the medium. When you add calcium and ATP to the medium, you observe phosphate production for only a short period of time. Only after the addition of calcimycin , a molecule that makes membranes selectively permeable to calcium, do you observe sustained phosphate production. Explain.

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter3: The Plasma Membrane And Membrane Potential

Section: Chapter Questions

Problem 6RE

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