Chapter 19/20 Viruses/Biotechnology

Lytic Cycle: Virulent Virus replicates genetic material Host cell creates new viruses Host cell breaks & spreads viruses Bacteria contain restriction enzymes for protection Examples: Flu, cold, chicken pox, polio, smallpox, EBV- mononucleosis

Lysogenic Cycle: Temperate Creates prophage Viral DNA gets copied and passed on with cell DNA Env. Trigger starts lytic cycle Viral DNA can create toxins Ex: HIV, HPV, Herpes, EBV- lymphoma

Retrovirus Genetic material enters cell Reverse transcriptase creates RNA-DNA hybrid, then copies DNA Inserts DNA into cell DNA Makes RNA & proteins Creates new viruses which spread & DNA gets copied and passed on to other cells

Viroids/Prions Viroids – circular RNA molecules, only infect plants Prions-infectious proteins – Little known – Misfolding proteins – NO treatment

DNA Cloning

Place gene of interest into plasmid 1.Cells with gene replicate and produce more genes 2.Multiple copies allows research and application 3.Genes make proteins & proteins can be isolated and used

Restriction Enzymes Cut up foreign DNA Used to make recombinant DNA DNA ligase

PCR DNA heated up Primers form, DNA pol. Creates new DNA Only requires small amounts of DNA Used a lot in forensics & genetic diagnosis

Gel Electrophoresis Restriction enzymes break DNA into segments Diff. sizes & charges go diff. distances Can isolate individuals genes & show DNA makeup Review your lab (you will get back Monday

RFLP (Restriction Fragment Length Polymorphism) SNPs (single nucleotide polymorphism) are changes single base pair variations Change the DNA segment recognized by restriction enzymes Creates new segments called RFLP Act as genetic markers