Question

Under certain circumstances, potassium ions ( K+ ) in a cell will move across the cell membrane from the inside to the outside. The potential inside the cell is −85.5 mV and the potential outside the cell is zero. What is the change in the electrical potential energy of a single potassium ion as it moves across the membrane? change in potential energy: J Does the potential energy of the potassium ions increase, decrease, or remain the same as the ions move from the inside to the outside? remain the same increase decrease

Answer 1

Answer 2

Potential energy of a charge particle in a potential is given by the following formula: Here, Uis the potential energy, q is the charge, and Vis the potential difference Potential energy of the K is given by the following equation (charge on the K 1.6022x10-19 c) U, = (1.6022 x 10-19 C)(-85.5 mV) ion is 16022x10- C)-85.5x10 V) Potential energy outside the cell is, U1.6022x10-19 C) (0 v) Hence, change in potential energy of the single potassium ion is 1.6022x1019 C(-85.5x103 V) 1.37x10-20 j Since inside voltage is negative hence, the potential energy inside the cell is negative and potential out side is 0 V hence, potential energy outside is 0 J. Hence, potential energy ncreases