bacterial transformation and transduction

DNA transformation is a process by which DNA can be transferred into bacteria.  Plasmids are DNA that is inputted into the bacteria.  The experiment is to test the different genes (usually foreign genes not native to the bacteria) in the DNA plasmids and whether transformation affect the bacteria.  First, we much examine the molecular form of bacterial transformation.  During rapid growth, the cell membrane of bacteria has pores, called adhesion zones.  The cell membrane is made up of lipid molecules that is negatively charged by phosphates.  The negatively charged membrane is repellent toward the DNA.  Calcium ions are added.  Lowering the temperature allows the negatively-charged phosphates to be stabilized, making them easier to shield.  By having a heat shock, the DNA can sweep through the cell membrane.  DNA must cross the membrane in order to get into the bacteria.(This molecular process is called transduction).  Scientists, Boyer and Cohen, tried to input DNA plasmids into E.coli.  As stated before, the heat shock allows the plasmid to emerge into the bacteria.  The scientists put the bacteria with the plasmids into a petri dish and grow the culture with antibiotics tetracyline and kanamycin.  Only transformed bacteria containing both kinds of resistance genes in the DNA plasmids can survive in the presence of both antibiotics.  This is possible on two conditions: first which the two genes are available on one plasmid or that the genes are present on two set of plasmids.