Lecture 12.*”Prokaryotes”: cause they are paraphyletic.1. Differentiate the “prokaryotes” from the eukaryotesProkaryotes EukaryotesUnicellularity No multicellular: univellularMulti or uniInternal structure No membrane boundedorganellesNo cytoskeletonNo enzymeHighly compartmentalized, many organellesChromosomes Single, circular DNA chromosome.Membrane-bounded nucleus with multiple linear chromosome.Cell division Binary fission MitosisGene Transfer Lateral transfer RecombinationCell wall Ubiquitous (peptidoglycan; bacteria, polymer of sugars and amino amids that forms in interior cell wall or psuedomurein; archean, similar polymer to peptidoglycan) In some organisms (nopeptidoglycan)If Gram stain-> pink/redBacteria:Gm (+): multiple peptidoglycan layers -> purple stained. Gm (-): one thin peptidoglycan layer -> red/ pink stained. Archaeans are all Gm (-) since they don’t have peptidoglycan layer.Flagella -Simple, single fiber-rigid-they spin in order to moveVery complex, 9+2 structureSize -Typically small-very misleading -> Typically large.initially notice one. *Horizontal transfer: do not give a trait via reproduction- Web of life- ex) Thermotoga maritime: survive in extremely high pemperature. Insignificant traits are not passed vertically but can move one branch to another. (One species to another.)2. Bacteria classificationA. Shape (rod: bacillus, sphere: coccus, spiral: spirillum) B. Metabolisma. Respiration- Aerobes: need oxygen to live- Anaerobe: poisoned by oxygen- Facultative anaerobes: it can live both anaerobe and aerobe environment. They prefer to be at the top since aerobic respiration generates more ATP.- Aerotolerant anaerobes: do not require oxygen as they metabolize energy anaerobically. Unlike obligate anaerobes however, they are not poisoned be oxygen. They can be found evenly spread throughout the test tube. b. Food(1) Autotrophs (self feeders): light+water -> break down CO2 to make sugar.- Photoautotrophs: catch light and produce oxygen as by product. Need chlorophyll- Chemoautotrophs: gain energy by breaking the chemical bonds of inorganic chemicals to make organic material; sugars. They use this energy instead of the energy from sun light to break down carbon dioxide in order to get carbon. (no need sunlight)(2) Heterotrophs (other feeders): including decomposers and pathogens.- Photoheterotroph: use bacterio-chlorophyll and hydrogen sulfide. Cannot break down carbon dioxide, so carbon source is from other organism. Energy comes from sun butcarbon comes from eating other organism. C. Gram + or –D. Motile or notE. Photosynthetic or notF. Unicellular, colony forming, or filamentous- Some prokaryotes are colonial and some are filamentous, while some exist simply as individual cells.3. BacteriaA. Gram (+) bacteriaa. Low GC Gram (+) can be dormant for long periods (endospores)- In harsh environment, most of the member can produce endospores that can survive in harsh (high temperature) environment.- Some endospores may not activate for millions of year and come back from dormancy. When it is active, it divides to form multiple new parent cell.- Toxicb. High GC Gram (+) Bacteria are filamentous.- Look like fungi.- Reproduce: break out from original cell.- Source of anti-bacterial; bacteria kill other bacteria- Ex) Actinomyces sp: break down organic soil; smell after rain.B. Gram (-) bacteriaa. Hyperthermophilic bacteria (ex. Thermotoga Maritima) and hadobacterica (ex. Deinococcus Radiodurans) are extreme heat lovers.- There is not a lot phenotypically difference between them.b. Cyanobacteria are critical photoautotrophs.- Not single species, very diverse group- Same internal membrane system- Chloroplasts are derived from cyanobacteria; photosynthesis- Gram (-)- Bloom of cyanobacteria. (giant colony)c. Spirochetes have axial filaments and are common pathogens.- Gram (-)- Heterotrophs- Mobility: axial filaments rotate inside spiral kit.- Borrelia burgdorferi causes lyme disease.- Syphilis.d. Chlamydias are the smallest, obligate parasitic cocci.- Gram (-)- Cause STD- Difficult iron infectione. Proteobacteria have very diverse metabolic pathways.- hargest, most diverse.- Purple bacteria- Photoheterotrophs, photoautotrophs, cheoheterotrophs, chemoautotrophs.4. ArchaeaA. Many Crenarcheota but not all love hot, cold, or acidic environments.- Abnormal shape- Abnormal enbironment- Thermophilic- Cryophilic (love cold)- Acidophilic - Extremophile- Most common marine archaean- Fixation of “Carbon”-> help for green house effect.B. Euryarcheota contains the methanogens; produce methan-> cause green house effect.- Halophiles (love salt)- Extreme thermophiles
View Full Document
Unlocking...