Final answer:
Group translocation aids in the retention of molecules drawn out of the cell by diffusion by chemically modifying the molecules so that they do not need to be transported against an unfavorable concentration gradient.
Step-by-step explanation:
Group translocation is a type of transport mechanism in bacteria that aids in the retention of needed molecules. When molecules are drawn out of the cell by diffusion, group translocation chemically modifies these molecules so that they do not need to be transported against an unfavorable concentration gradient.
One example of group translocation is the bacterial phosphotransferase system, which adds phosphate ions to glucose or other sugars upon entry into the cell. This modification allows the sugars to be retained inside the cell, where they are needed for sugar metabolism.