Amino acids are usually taken up into animal cells using a coupled transport system in the plasma membrane. Clearly stated in th
e space below whether this transport mechanism requires energy. If it does not require energy, explain why no energy is needed. If it does require energy, state the source of energy.
In the coupled transport system, coupled carriers couple the inward transport of one solute across the membrane to the outward transport of other solutes across the membrane. The tight bonding that occurs between the transport of two solutes allows these carriers to utilize the energy stored in one solute, usually an ion, to facilitate transport of the other. With this way, the free energy released during the movement of an ion down an electrochemical gradient is utilized as the driving force to transport other solutes inwards, against their electrochemical gradient.
