Initials: Cell Biology Exam 1 Use the following image of the Na -K ATPase to ans
ID: 90210 • Letter: I
Question
Initials: Cell Biology Exam 1 Use the following image of the Na -K ATPase to answer questions 27 and 28. ATP high energy 27) The e is also known as the Na+-K+ pump is represented in the figure above. It is responsible maintaining the high extracellular sodium ion concentration and the high for intracellular potassium ion concentration. Which of the following statements regarding the is FALSE? a) ltactively pumps Na out of and K into a cell against their electrochemical gradients. b) The pump hydrolyzes ATP to phosphorylate itself, causing a conformational change transporting Na out of the cell. c) pump binds to which acts as a molecular switch. to its original confirmation d) Dephosphorylation of the pump causes the pump to return transporting K into the cell. 8) What causes the pump to return to its original confirmation and release the K into the cytosolic space? a) The pump is dephosphorylated b) The pump is phosphorylated c) ADP is bound d) ATP is hydrolyzedExplanation / Answer
Answer
27) Option C is a False statement because the pump does not bind with ATP rather it get phosphorylated by hydrolyzing the ATP into ADP.
28) Option a is the right answer because dephosphorylation causes a conformational change in the cytosolic region that triggers the release of K+ ion into the cytosolic space.