Question

Describe in detail how ATPase works for ATP production and why cells may use their ATPase in reverse.

Answer 1

ATPase is ATP synthase which creates ATP molecules by ADP and Pi.

Formation of ATP from ADP and Pi is energetically unfavorable. In order to drive this reaction forward, ATP synthase couples ATP synthesis during cellular respiration to an electrochemical gradient created by the difference in proton (H⁺) concentration across the mitochondrial membrane in eukaryotes or the plasma membrane in bacteria.

It has main two sub units F0 and F1 which functions in a rotaing manner.

F0 : the portion embedded in the inner mitochondrial membrane

F1 : ATPase the portion projecting into the matrix of the mitochondrion

Protons that have accumulated in the intermembrane space enter the F0 complex and exit from it into the matrix. The energy they give up as they travel down their concentration gradient rotates F0 and its stalk in a clockwise direction. As it does so, it induces repeating conformational changes in the head proteins that enable them to convert ADP and Pi into ATP.