Refer to the figure below, which is being created to illustrate secondary active transport. The small red circles represent the molecules being transported, and the H⁺ symbols represent hydrogen ions.The natural concentration gradient of the red molecules is shown.The hydrogen ion gradient was established by a membrane protein that is not shown.Given this information, which symbol should appear in the oval to indicate the direction of movement of hydrogen ions and red molecules?

Question

Quizplus · Accepted Answer

The red molecules are being transported against their concentration gradient, so the movement of hydrogen ions must be in the same direction as the arrow indicating the energy input. Choice B is the only option that shows hydrogen ions moving in the same direction as the arrow, indicating the direction of energy input for secondary active transport.

Refer to the Figure Below, Which Is Being Created to Illustrate