Question

how does coupled transport allow a molecule to be transported against the electrochemical gradient? a) a co - transported molecule travels down an electrochemical gradient in either direction b) it uses energy from atp c) another molecule binds to one side of the transporter driving a conformational change d) it uses energy from light

Explanation:

Coupled transport involves a co - transported molecule moving down its electrochemical gradient. This downhill movement provides the energy to drive another molecule against its electrochemical gradient. It does not directly use ATP or light energy in the way described in options b and d. Option c describes a general mechanism of transporter action but not the essence of coupled transport.

Answer:

A. A co - transported molecule travels down an electrochemical gradient in either direction