Understanding the Classification of Organisms: A Comprehensive Overview

Classification & the New Taxonomy Chapters 26 – 34

Solar System Finding commonality in variety Earth • Organisms classified from most general group, _________, down to most specific, ________ • domain, kingdom, phylum, class, order, family, genus, species No. America U. S. N. Y. New York City Queens use the mnemonic! Forest Hills

Eukaryote Prokaryote Archaebacteria&Bacteria Classification • ______5 Kingdom system • Monera, Protists, Plants, Fungi, Animals • ______3 Domain system • reflects a greater understanding of evolution & molecular evidence • ________________________ • ________________________ • ________________________ • ____________ • ____________ • ____________ • ____________

KingdomBacteria KingdomArchaebacteria KingdomProtist KingdomFungi KingdomPlant KingdomAnimal

The Evolutionary Perspective

Fungi Animalia Kingdoms absorptivenutrition ingestivenutrition Plantae autotrophs heterotrophs Protista uni- tomulticellular multicellular Eubacteria Archaebacteria prokaryotes eukaryotes Single-celled ancestor

Domain Bacteria Domain Archaea Domain Eukarya Common ancestor Prokaryotes Domain Bacteria Domain Archaebacteria

Bacteria live EVERYWHERE! • Bacteria live in all ecosystems • on plants & animals • in plants & animals • in the soil • in depths of the oceans • in extreme cold • in extreme hot • in extreme salt • on the living • on the dead Microbes alwaysfind a way tomake a living!

Bacterial diversity rods and spheres and spirals… Oh My!

eukaryote cell prokaryotecell Prokaryote Structure • Unicellular • ______________________ • Size • ______________________ • 1 micron (1um) • Internal structure • __________________________ • no membrane-bound organelles • only ribosomes • __________________________ • not wrapped around proteins

Prokaryote vs. Eukaryote Chromosome Prokaryote Eukaryote double helix

Fig. 27-8 Chromosome Plasmids 1 µm

mitochondria chloroplast Variations in Cell Interior cyanobacterium(photosythetic) bacterium aerobic bacterium internal membranesfor respirationlike a mitochondrion(cristae) internal membranesfor photosynthesislike a chloroplast(thylakoids)

outer membrane of lipopolysaccharides __________________ __________________ peptide side chains outer membrane cell wall peptidoglycan cell wall peptidoglycan plasma membrane plasma membrane protein Prokaryote Cell Wall Structure That’simportant foryour doctorto know! __________________= polysaccharides + amino acid chains __________________= lipids + polysaccharides

Fig. 27-3 Carbohydrate portion of lipopolysaccharide Outer membrane Peptidoglycan layer Cell wall Cell wall Peptidoglycan layer Plasma membrane Plasma membrane Protein Protein Gram- positive bacteria Gram- negative bacteria 20 µm (b) Gram-negative: crystal violet is easily rinsed away, revealing red dye. (a) Gram-positive: peptidoglycan traps crystal violet.

Other prokaryotic cell structures • Capsule • Fimbriae • Sex pili

Fig. 27-4 200 nm Capsule

Fig. 27-5 Fimbriae 200 nm

Fig. 27-6 Flagellum Filament 50 nm Cell wall Hook Basal apparatus Plasma membrane

Prokaryotic metabolism • How do bacteria acquire their energy & nutrients? • ________________ • photosynthetic bacteria • ________________ • oxidize inorganic compounds • nitrogen, sulfur, hydrogen… • ________________ • live on plant & animal matter • decomposers & pathogens

Table 27-1

The Role of Oxygen in Metabolism • Prokaryotic metabolism varies with respect to O2: • ________________require O2 for cellular respiration • ________________are poisoned by O2 and use fermentation or anaerobic respiration • ________________can survive with or without O2

Metabolic Cooperation • Cooperation between prokaryotes allows them to use environmental resources they could not use as individual cells

Fig. 27-14 Photosynthetic cells Heterocyte 20 µm

Fig. 27-15 1 µm

Reproduction and Adaptation • Prokaryotes reproduce quickly by binary fission and can divide every 1–3 hours • Many prokaryotes form metabolically inactive ______________, which can remain viable in harsh conditions for centuries

Fig. 27-9 Endospore 0.3 µm

Genetic variation in bacteria • Rapid Reproduction • bacteria can reproduce every 20 minutes • _________________ • Mutations • error rate in copying DNA • 1 in every 200 bacteria has a mutation • you have billions of E. coli in your gut! • lots of mutation potential! • Genetic recombination • bacteria swap genes • __________________ • __________________ • __________________ conjugation

Transformation and Transduction • A prokaryotic cell can take up and incorporate foreign DNA from the surrounding environment in a process called ____________________ • _________________is the movement of genes between bacteria by bacteriophages (viruses that infect bacteria)

Fig. 27-11-1 Phage DNA A+ B+ A+ B+ Donor cell

Fig. 27-11-2 Phage DNA A+ B+ A+ B+ Donor cell A+

Fig. 27-11-3 Phage DNA A+ B+ A+ B+ Donor cell A+ Recombination A+ A– B– Recipient cell

Fig. 27-11-4 Phage DNA A+ B+ A+ B+ Donor cell A+ Recombination A+ A– B– Recipient cell A+ B– Recombinant cell

Conjugation and Plasmids • Conjugation: __________________________________________________________________________ • ___________ allow cells to connect and pull together for DNA transfer • A piece of DNA called the ____________ is required for the production of sex pili • The F factor can exist as ________________ ___________ or as _____________________ ______________

Fig. 27-12 1 µm Sex pilus

Fig. 27-13 The F Factor as a Plasmid F plasmid Bacterial chromosome F+ cell F+ cell Mating bridge F– cell F+ cell Bacterial chromosome (a) Conjugation and transfer of an F plasmid Recombinant F– bacterium A+ Hfr cell A+ A+ A+ F factor A– A+ A– A+ A– A– F– cell (b) Conjugation and transfer of part of an Hfr bacterial chromosome

Fig. 27-13-1 Bacterial chromosome F plasmid F+ cell Mating bridge F– cell Bacterial chromosome (a) Conjugation and transfer of an F plasmid

Fig. 27-13-2 Bacterial chromosome F plasmid F+ cell Mating bridge F– cell Bacterial chromosome (a) Conjugation and transfer of an F plasmid

Fig. 27-13-3 Bacterial chromosome F plasmid F+ cell F+ cell Mating bridge F– cell F+ cell Bacterial chromosome (a) Conjugation and transfer of an F plasmid

Fig. 27-13-4 The F Factor in the Chromosome A+ Hfr cell A+ A+ F factor A– A– F– cell (b) Conjugation and transfer of part of an Hfr bacterial chromosome

Fig. 27-13-5 A+ Hfr cell A+ A+ A+ F factor A– A+ A– A– F– cell (b) Conjugation and transfer of part of an Hfr bacterial chromosome

Fig. 27-13-6 Recombinant F– bacterium A+ Hfr cell A+ A+ A+ F factor A– A+ A– A+ A– A– F– cell (b) Conjugation and transfer of part of an Hfr bacterial chromosome

R Plasmids and Antibiotic Resistance • R plasmids carry genes for antibiotic resistance • Antibiotics select for bacteria with genes that are resistant to the antibiotics • Antibiotic resistant strains of bacteria are becoming more common

Bacteria as pathogens • Disease-causing microbes • _________________ • wilts, fruit rot, blights • _________________ • tooth decay, ulcers • anthrax, botulism • plague, leprosy, “flesh-eating” disease • STDs: gonorrhea, chlamydia • typhoid, cholera • TB, pneumonia • lyme disease

Fig. 27-21 5 µm

Bacteria as beneficial (& necessary) • Life on Earth is dependent on bacteria • _______________________ • recycling of nutrients from dead to living • _______________________ • only organisms that can fix N from atmosphere • needed for synthesis of proteins & nucleic acids • plant root nodules • _______________________ • digest cellulose for herbivores • cellulase enzyme • produce vitamins K & B12 for humans • _______________________ • from yogurt to insulin

Fig. 27-22a (a)

Got any Questions?? Ask da’ BacterialBoss!

You should now be able to: • Distinguish between the cell walls of gram-positive and gram-negative bacteria • State the function of the following features: capsule, fimbriae, sex pilus, nucleoid, plasmid, and endospore • Explain how R plasmids confer antibiotic resistance on bacteria

Distinguish among the following sets of terms: photoautotrophs, chemoautotrophs, photoheterotrophs, and chemoheterotrophs; obligate aerobe, facultative anaerobe, and obligate anaerobe; mutualism, commensalism, and parasitism; exotoxins and endotoxins

Understanding the Classification of Organisms: A Comprehensive Overview