<prompt> NaK pump which enzyme is used -ATPaseGTPaseAcetyl CoANone of these  <response>: Sodium-potassium pump is the most important pump for primary active transport Q in the body.Na -K pump is an electrogenic pump Q that is responsible for maintaining the Na and K concentration difference across the cell membrane.Na - K pump extrudes 3 Na out from the cell and at the same time pump 2K into the cell Q , i.e., Coupling ratio of Na K pump is 3 : 2 Q . Na and K transport by Na - K pump is primary active transport Q and both Na and K are transported against concentration gradient Qintracellular fluid has high concentration of K and ECF has high concentration of Na - .Na K pump uses energy by hydrolysing ATP; this pump contains ATPase activity Q.Na - K pump is a carrier protein which is a heterodimer 0 made up of two separate globular proteins: a larger one called α-subunit with a molecular weight of 100,000 and a smaller one called β-subunit, with a molecular weight of about 55,000. Both α- and β- subunits span across the membrane with intracellular and extracellular sites. Na and K transport occurs through a-subunits.Intracellular portion of a-subunit has three Na binding sites three receptor sites for Na , an ATP binding site, a phosphorylating site and ATPase activity Q.Extracellular portion Q has two K binding sites two receptor sites for K , and an ouabain binding site Q.The β- subunit has three extracellular glycosylation sites Q, all of which appear to have attached carbohydrate residue.The Na - K pump is an electrogenic pump Q since it produces a net movement of positive charge out of the cell.Thus, besides maintaining the ionic composition of the intracellular fluid, the Na - K pump helps to maintain the electrochemical potential difference across the cell membrane.However, Na - K pump contributes only 4 millivolts to the total resting membrane potential of 90 volts which is almost negligible Q.Active transport of Na and K - is one of the major energy-using processes in the body.On average, it accounts for about 24 of the energy utilized by cell and in neurons, it accounts for 70. o Activity of Na - K pump is stimulated by the increased intracellular concentration of Na ,thyroid hormones, aldosterone and insulin. Pump activity is inhibited by CHF, CRF, digoxin toxicity and dopamine. 