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Cell Structure and Function in the Bacteria and Archaea © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 4 NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ChapterCh t PreviewPi and dK Key Concepts © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 4.1 DiversityNOT Among FOR the Bacteria SALE and OR Archaea DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 1. The Bacteria are classified into several Cell Structure major phyla. 2. The Archaea are currently classified into two major phyla. © Jones4.2 Cell & Shapes Bartlett and Learning,Arrangements LLC and© Jones & FunctionBartlett Learning, LLC NOT FOR3. ManySALE bacterial OR cells DISTRIBUTION have a rod, spherical, or NOT FOR SALE OR DISTRIBUTION spiral shape and are organized into a specific cellular arrangement. 4.3 An Overview to Bacterial and Archaeal in the Bacteria Cell Structure 4. Bacterial and archaeal cells© Jonesare organized & Bartlettat Learning, LLC © Jones & Bartlett Learning, LLC the cellular and molecularNOT levels. FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4.4 External Cell Structures and Archaea 5. Pili allow cells to attach to surfaces or other cells. 6. Flagella provide motility. 7. A glycocalyx protects against desiccation, Our planet has always been in the “Age of Bacteria,” ever since attaches© Jones cells to surfaces, & Bartlett and helps Learning, LLCthe first fossils—bacteria© of Jones course—were & Bartlett entombed Learning, in rocks LLCmore pathogensNOT evade FOR the SALE immune system.OR DISTRIBUTIONthan 3 billion years ago. NOTOn any FOR possible, SALE reasonable OR DISTRIBUTION criterion, 4.5 The Cell Envelope bacteria are—and always have been—the dominant forms of life 8. Bacterial cell walls help maintain cell shape and protect the cell membrane from rupture. on Earth. 9. Archaeal cell walls have crystalline layers. —Paleontologist Stephen J. Gould (1941–2002) 10. Molecules and ions cross the cell membrane © Jones &by Bartlett facilitated diffusionLearning, or active LLC transport. © Jones & Bartlett Learning, LLC “Double, double toil and trouble; Fire burn, and cauldron bubble” is NOT FOR11. ArchaealSALE membranes OR DISTRIBUTION are structurally unique. NOT FOR SALE OR DISTRIBUTION 4.6 The Cell Cytoplasm and Internal the refrain repeated several times by the chanting witches in Shakespeare’s Structures Macbeth (Act IV, Scene 1). This image of a hot, boiling cauldron actually 12. The nucleoid contains the cell’s essential describes the environment in which many bacterial, and especially genetic information. archaeal, species happily grow! For example, some species can be 13. Plasmids contain nonessential© Jones genetic & Bartlettisolated Learning, from LLChot springs or the hot, acidic© mudJones pits & of Bartlett volcanic ventsLearning, LLC information. NOT FOR SALE ORFIGURE DISTRIBUTION 4.1 NOT FOR SALE OR DISTRIBUTION 14. Ribosomes, microcompartments, and ( ). inclusions carry out specific intracellular When the eminent evolutionary biologist and geologist Stephen functions. J. Gould wrote the opening quote of this chapter, he as well as most 15. Cytoskeletal proteins regulate cell division microbiologists had no idea that embedded in these “bacteria” was and help determine cell shape. another whole domain of organisms. Thanks to the pioneering studies MICRO©I NQUIRYJones 4: The& BartlettProkaryote/Eukaryote Learning, LLC © Jones & Bartlett Learning, LLC ModeNOTl FOR SALE OR DISTRIBUTIONof Carl Woese and his colleagues,NOT FOR it SALE now is OR quite DISTRIBUTION evident there are two distinctly different groups of “prokaryotes”—the Bacteria and the Archaea (see Chapter 3). Many of the organisms Woese and others studied are organisms that would live a happy life in a witch’s cauldron © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 96 © Jones and Bartlett Publishers. NOT FOR SALE OR DISTRIBUTION 4.1 Diversity Among the Bacteria and Archaea 97 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION (A) (B) FIGURE 4.1 Life at the Edge. Bacterial and archaeal extremophiles have been isolated from the edges of natural cauldrons, including (A) the Grand © JonesPrismatic & Bartlett Spring inLearning, Yellowstone National LLC Park, Wyoming, where the ©water Jones of the hot& springBartlett is over Learning, 70ºC, or (B) the LLC mud pools surrounding sulfurous NOT FORsteam SALE vents ofOR the SolfataraDISTRIBUTION Crater in Pozzuoli, Italy, where the mudNOT has a veryFOR low SALEpH and a ORtemperature DISTRIBUTION above 90ºC. »» How do extremophiles survive under these extreme conditions? because they can grow© atJones high temperatures,& Bartlett Learning, as different LLC from each other as they are© Jonesfrom the & Bartlett Learning, LLC produce methane gas,NOT or survive FOR inSALE extremely OR DISTRIBUTIONEukarya. NOT FOR SALE OR DISTRIBUTION acidic and hot environments—a real cauldron! Termed extremophiles, these members of the As more microbes have had their complete domains Bacteria and Archaea have a unique genomes sequenced, it now is clear that there are genetic makeup and have adapted to extreme envi- unique as well as shared characteristics between © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ronmental conditions. species in the domains Bacteria and Archaea. InNOT fact, Gould’s FOR SALE “first fossils” OR DISTRIBUTION may have been In this chapter,NOT we examine FOR SALE briefly OR some DISTRIBUTION archaeal species. Many microbiologists believe of the organisms in these two domains. However, the ancestors of today’s archaeal species might because so many pathogens of humans are in represent a type of organism that first inhabited the domain Bacteria, we emphasize structure © Jonesplanet & Bartlett Earth whenLearning, it was LLCa young, hot place. within© Jonesthis domain. & Bartlett As we Learning,see in this chapter, LLC NOT FORThese SALE unique OR characteristics DISTRIBUTION led Woese to propose a studyNOT of FOR the structural SALE OR features DISTRIBUTION of bacterial these organisms be lumped together and called the cells provides a window to their activities and Archaebacteria (archae = “ancient”). illustrates how the Bacteria relate to other living Since then, the domain name has been organisms. changed to Archaea because (1) not all members As we examine bacterial (and archaeal) cell are extremophiles or ©related Jones to these& Bartlett possible Learning, structure, LLC we can assess the dogmatic© statement Jones & Bartlett Learning, LLC ancient ancestors and (2)NOT they FOR are not SALE Bacteria— OR DISTRIBUTIONthat these cells are characterized byNOT a lack FOR of a SALE OR DISTRIBUTION they are Archaea. Some might also debate using cell nucleus and internal membrane-bound organ- the term prokaryotes when referring to both elles. Before you finish this chapter, you will be domains, as organisms in the two domains are equipped to revise this view. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4.1 Diversity Among the Bacteria and Archaea In this section, we discuss bacterial and archaeal bacterial and archaeal species and a suspected diversity using the current classification scheme, 10 million species. In this section, we will high- © Joneswhich & Bartlett is based Learning, in large LLCpart on nucleotide light© a Jonesfew phyla & andBartlett groups Learning, using the phyloge- LLC NOT FORsequence SALE data.OR DISTRIBUTION There are some 7,000 known neticNOT tree inFOR FIGURE SALE 4.2 . OR DISTRIBUTION © Jones and Bartlett Publishers. NOT FOR SALE OR DISTRIBUTION 98 CHAPTER 4 Cell Structure and Function in the Bacteria and Archaea © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ARCHAEA BACTERIA (2 major phyla) (>25 major phyla) Euryarchaeota Crenarchaeota Cyanobacteria © Jones & Bartlett Learning, LLC © Jones & BartlettExtreme Learning, LLC Gram-positive halophiles NOT FORbacteria SALE OR DISTRIBUTIONChlamydia MethanogensNOT FOR SALE OR DISTRIBUTION Proteobacteria Spirochaetes © Jones & Bartlett Learning, LLC Hyperthermophiles© Jones & Bartlett Learning,Eukarya LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Hyperthermophiles LAST UNIVERSAL © Jones & Bartlett Learning, LLC © Jones & BartlettCOMMON ANCESTORLearning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION FIGURE 4.2 The Phylogenetic Tree of Bacteria and Archaea. The tree shows several of the bacterial and archaeal lineages discussed in this chapter. »» What is common to the branch base of both the Bacteria and Archaea? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC The NOTDomain FOR Bacteria SALE ORContains DISTRIBUTION Some They can be isolatedNOT from FOR Arctic SALE ice, thermal OR DISTRIBUTIONhot of the Most Studied Microbial springs, the fringes of space, and the tissues of ani- Organisms mals. Bacterial species, along with their archaeal KEY CONCEPT relatives, have so completely colonized every part 1. The Bacteria are classified into several
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