Question

The Na+/K+ pump transports 2 K+ into the cell and 3 Nat out of the cell under the use of ATP. Under normal circumstances, the concentration of K+ inside the cell is 140 mm, while the [K] outside of the cell is 6 mM. The concentration of Nat inside the cell is 16 mM, while the [Na] outside the cell is 145 mm. The membranpotential is -0.07 V The temperature is 37°C/310,15K c) Calculate how much energy (kJ/mol it takes to maintain these concentrations For the reaction: ATP + H2O → ADP + P (under standard conditions) AG'= -30,5 kJ/mol e) How many moles ATP does the sodium/potassium pump need to hydrolyze under standard conditions to get to the concentration differences? Explain why this number is smaller under physiological conditions to reach these concentrations.

Answer 1

(c) As you see in the given statement, the concentration of K+ ion is higher inside the cell and Na+ ion concentration is lower. While outside the cell the concentration of Na+ ion is higher and K+ ion is lower, when Na+ tend to move to inside the cell to maintain the concentration gradient then a voltage across the membrane encourages this movement of ion, in this type of ion movement 2 K+ ions move outside the cell and 3 Na+ ion move inside the cell this type movement is operated by voltage (-0.04 to -0.8 V), not by ATP molecule. for this type of ion movement, no Energy molecule is required, This type of concentration gradient is called electrochemical gradient and such type of transportation is called Passive transportation.

(e) When the concentration of sodium ion (Na+) is higher inside the cell and lowe outside the cell, on the other hand, the concentration of Potassium is lower inside the cell (cytoplasm) and higher outside the cell. In such a case, Na+ transport outside the cell and K+ move inside the cell to maintain the concentration. For the transportation of Na+ and K+ ion, One mole of ATP is required to 3 Na+ and 2K+.

Three Na+ ions come near to the K+/Na+ channel and one ATP molecule attached to this channel and hydrolyzed into ADP and Pi (inorganic phosphate) this Pi attached to open K+/Na+ Channel, Once the pump opens 3 Na+ ions release from the cell and 2 K+ come inside the cell. This type of transport is called Active transport where ATP mole is utilized in the transportation of Ions or molecules,