Biology 102Lecture 12Outline of last lecture:I. ProkaryotesOutline of current lecture:I. Clicker questionsII. PilliIII. EndosporesIV. Examples of bacteriaClicker QuestionsWhy are pili important for pathogenic organisms? Say for example, why does a bacteria that infects the urinary tract need pili?A. So they can attach to the host B. So they aren’t washed awayC. So they can exchange genetic materialD. All of the aboveWhat is the difference between a pathogenic strain of E. coli and a normal flora (nonpathogenic)e. coli?A. Mutation in pathogen allows for toxin production that normal bacteria lacksB. Conjugation shares DNA that codes for a toxin C. TransformationD. Transduction(All are right, but B is the most accurate)Pili Pili: little appendages with receptors on the end - Hollow connecting tube: exchange genetic materialo Reproduce asexually through binary fission Daughter cells: genetically identical to parent cell, only way it can be different or have genetic changes is if a mutation occurs or there’s an erroro Conjugation- when they join together Sex pilus, have to have the gene for piluso Plasmid- small circular pieces of DNABiology 102 They have extra genes Ex. antibiotic resistance Toxin production genes Pilus formation Normal flora doesn’t have a plasmid, the plasmid with a plasmid is what makes the toxin and that’s what makes you sickEndosporesEndospores- structure that certain bacteria can make, only certain allows them to withstand harsh conditions.- Thick coat surrounds the DNA or genetic materialo Other parts die away and that coat and DNA is left o Structures can lay dormant for thousands of yearsExamples of BacteriaBacillus anthracis (Anthrax)- Can form endospores - Found in soil, in sheep and grazing animals - If an animal falls and dies, this bacteria decomposes it- Animals to humans: could be spread through skin contact - Can be used in biological warfareClostridium tetani (tetanus)- Soil bacteria, decomposer- rigid muscles dirt of any kind- Endospores from this guy all in the dirt remain for thousands of yearsClostrium botulinum (Botox)- Big concern for food, doesn’t kill the endospores - Botox- paralysis, paralyzes your muscles if
View Full Document
Unlocking...