Which of the Following is a Pump That Hydrolyzes Two

Question

Which of the following is a pump that hydrolyzes two ATP molecules per transport cycle?
A) The cystic fibrosis transmembrane conductance regulator protein
B) The multidrug resistance protein
C) The Na⁺-K⁺ pump
D) The Ca²⁺-pump
E) The V-type ATPase

Accepted Answer

The multidrug resistance protein is an ABC transporter that binds to and hydrolyzes two ATP molecules for the transport of each substrate. The cystic fibrosis transmembrane conductance regulator protein is also an ABC superfamily member, but it is a channel and hydrolyzes ATP just for gating.