1. Compare and contrast simple transporters, the phosphotransferase system, and ABC transporters in terms of (1) energy source, (2) chemical alterations of the solute during transport, and (3) number of proteins required.

The transporters are required for the transport of specific molecules into and out of the cell. These transporters are located in the cell membrane or on the receptors of the cell.

Simple transporters generally obtain their energy by the difference created by the proton motive force. The ions especially hydrogen ions alters during the transport. Only simple proteins are required for this type of transport.

Phosphotransferase System obtain their energy by the transfer of the specific substance like phosphoenol pyruvate. This transporter atleast requires up to five protein. The phosphate ions are altered during the transport. This transporter is more common in prokaryotes.

ABC transporters contains the N and C terminal domain. Multiple pass transmembrane proteins are required for this type of transport. This transporters require ATP for the binding and dissociation of proteins.

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