Binding proteins can be selectively released from the periplasm by subjecting cells to osmotic shock , rendering the transport system much less active. Osmotic shock releases the periplasmic HisJ histidine-binding protein from the periplasm, rendering the system unable to transport histidine efficiently. D. Group translocation. Group translocation reactions chemically alter a substrate molecule during the process of uptake, usually to the first metabolizeable intermediate in a metabolic pathway. At this point, one of two things can happen.
Many bacteria have the ability to travel from one place to another, a process known as motility .
Several motility mechanisms exist. Motile bacteria exhibit apparently directed movement toward favorable environments and away from unfavorable ones. In order to understand taxis, it is essential to understand motility first. The best-characterized systems are in E. coli, S. typhimurium, and B. subtilis . When bacteria are presented with no stimulus, they run for approx.