Conjugation*Transfer of DNA from one cell to another- requires physical contact*Involves transfer of an F factor-contains genes for conjugationF 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 HfrF+ 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 resistanceHfr cell donor conjugation*One strand of chromosome moves across-Not all of the chromosomal DNA is transferredOther 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 environmentCell membraneLipids*incudes C, H & O*Found in many different types of biological structures-triacyglycerides (Fats)-PhotosHydrocarbons*Made of only hydrogen and carbon*serve as energy storage moleculesFats*Functions-Storage-StructureGlycerol- 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-liquidWhat 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 cholesterolPhospholipids*Contains:-Glycerol-Two fatty acids-Phosphate groups Lipid Bi…Cell membrane structure*Phospholipid bilayersFluid 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 membraneFactors 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
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