Conjugation Transfer of DNA from one cell to another requires physical contact Involves transfer of an F factor contains genes for conjugation F factor Contains genes required for conjugating cell without F factor called F Can be on a plasmid cell called F Can be in a chromosome Cell is called Hfr F cell doneor conjugation General steps sex pilus attaches cells and mating bridge forms One strand of F plasmid moves across bridge DNA is replicated and circularized R plasmids Small plasmids transferred by conjugating contains antibiotic resistance genes contribute to widespread antibiotic resistance Hfr cell donor conjugation One strand of chromosome moves across Not all of the chromosomal DNA is transferred Other mechanisms Transduction transfer of DNA from one cell to another by viruses Results in a new gene being transferred to a recipient cell after viral infection Transformation uptake of DNA from environment Cell membrane Lipids incudes C H O Found in many different types of biological structures triacyglycerides Fats Photos Hydrocarbons Made of only hydrogen and carbon serve as energy storage molecules Fats Functions Storage Structure Glycerol one of three dehydration reactions in the synthesis of a fat esterification release of H2O synthesized by dehydration reaction Between glycerol and fatty acids to form Triacylglycerol fat Three fatty acids linked to glycerol via ester linkages bond between a hydroxyl and carboxyl Saturated and unsaturated fats Saturated with H BUTTER no double bonds Solid Unsaturated fats with H OIL one or more double bonds liquid What about trans fats Made in the process of hydrogenation done to increase shelf life of foods Increase level of bad cholesterol decrease levels of good cholesterol Phospholipids Contains Glycerol Two fatty acids Phosphate groups Lipid Bi Cell membrane structure Phospholipid bilayers Fluid mosaic model Phospholipid form a bilayer Proteins embedded in membrane Cell membranes are fluid structures as soon as a membrane becomes like butter and less like oil the cell will parish Phospholipids can switch positions 10 million times second very rapid movement Moving with respect to each other Proteins move slowly Cannot preform a Flip flop once per month max Must stay on one side of a membrane cannot flip to the other side of the membrane Factors affecting fluidity Temperature Can increase or decrease fluidity Heating up can increase fluidity Low temperatures have to have a composition of lipids in membrane to keep them in motion too Unsaturated hydrocarbons Increase fluidity Membrane permeability
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