Question

In certain cells, a transport protein moves one calcium ion out of the cell against its concentration gradient while allowing the movement of three sodium ions into the cell down sodium's electrochemical gradient. Which of the following CORRECTLY describes this cotransport of calcium and sodium?a. primary active transport by an antiporterb. primary active transport by a symporterc. secendory active transport by a symporter

d. secendory active transport by an antiporter

Answer 1

d. secondary active transport by an antiporter

Step-by-step explanation:

Secondary active transport is a type of transport which uses gradient produces by another protien using ATP. It has two methods :

1) Symport : Solutes flow in same direction of the ion gradient (cotransport) as in the case of sodium glucose transporter

2) Antiport : Ions flow in one direction to generate the energy to transport the solutes in other direction .

Na/Ca exchanger is basically removing Calcium ions from the cell by inward flow of Na ions . Hence it is an example of secondary active transport by an antiporter