Question

Given the type of transporter as determined in Part 1, choose all of the correct statements below that relate to the function of the Na+/Ca2+ transporter

-the transporter directly uses ATP as an energy source for transporting ions
-Ca2+ is transported against its electrochemical gradient
-the transporter used the Na+ electrochemical gradient as an energy source for transporting ions
-Na+ is transported against its electrochemical gradient

Answer 1

The Na+/Ca2+ transporter utilizes secondary active transport, harnessing the electrochemical gradient of Na+ as an energy source, not ATP directly, to transport Ca2+ ions against their electrochemical gradient.

Step-by-step explanation:

The Na+/Ca2+ transporter is a critical component in maintaining ionic concentration within a cell. It does not directly use ATP; instead, it relies on the electrochemical gradient of Na+ as its energy source, making it an example of secondary active transport. Through this mechanism, Ca2+ is transported against its electrochemical gradient, utilizing the energy stored in the Na+ gradient which was previously established by primary active transport, often involving directly ATP-consuming processes like the sodium-potassium pump.

Thus, this transporter harnesses the energy from the Na+ gradient, rather than using ATP directly. As Na+ moves down its electrochemical gradient into the cell, Ca2+ is moved out of the cell against its gradient. This illustrates the principles of coupled transport, where the facilitation of one ion's passive transport is used to drive the active transport of another.