《环境工程微生物学》课程PPT教学课件（英文讲稿）Chapter 04 原核微生物 A Survey of Prokaryotic Cells and Microorganisms

TheMcGraw-HillCompaniesChapter 4ASurveyofFoundationsinProkaryoticCellsandMicrobiologyMicroorganismsEIGHTHEDTTIOKathleenParkTalaroBarryChessCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display

Chapter 4 A Survey of Prokaryotic Cells and Microorganisms Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display

Characteristics of Cells andLifeAll living things (single and multicellular) are made ofcells that share some common characteristics:- Basic shape - spherical, cubical, cylindrical- Internal content - cytoplasm, surrounded by amembrane- DNA chromosome(s), ribosomes, metabolic capabilitiesTwo basic cell types: eukaryotic and prokaryotic2

2 Characteristics of Cells and Life All living things (single and multicellular) are made of cells that share some common characteristics: – Basic shape – spherical, cubical, cylindrical – Internal content – cytoplasm, surrounded by a membrane – DNA chromosome(s), ribosomes, metabolic capabilities Two basic cell types: eukaryotic and prokaryotic

FLEXCharacteristicsofCellsEukaryotic cells: animals, plants, fungi, and protists- Contain membrane-bound organelles thatcompartmentalize the cytoplasm and perform specificfunctions- Contain double-membrane bound nucleus with DNAchromosomesProkaryotic cells: bacteria and archaea- No nucleus or other membrane-bound organellesCopyright The McGraw-HillCompanies, hc. Permis sion required for reproduction or dis playProkaryoticEukaryoticNucleusMitochondriaChromosomeRibosomesRibosomesCell wall CellmembraneFlagellumFlagellum3Cellmembrane

3 Characteristics of Cells Eukaryotic cells: animals, plants, fungi, and protists – Contain membrane-bound organelles that compartmentalize the cytoplasm and perform specific functions – Contain double-membrane bound nucleus with DNA chromosomes Prokaryotic cells: bacteria and archaea – No nucleus or other membrane-bound organelles Copyright © The McGraw -Hill Companies, Inc. Permission required for reproduction or display Cell membrane Nucleus Mitochondria Ribosomes Cell membrane Cell wall Flagellum Flagellum Chromosome Prokaryotic Eukaryotic Ribosomes

Characteristicsof Life: Reproduction and heredity - genome composedof DNA packed in chromosomes; produceoffspring sexually or asexuallyGrowth and development. Metabolism - chemical and physical lifeprocesses Movement and/or irritability - respond tointernal/external stimuli; self-propulsion of manyorganisms: Cell support, protection, and storage mechanisms- cell walls, vacuoles, granules and inclusionsTransportofnutrients andwaste4

4 Characteristics of Life • Reproduction and heredity – genome composed of DNA packed in chromosomes; produce offspring sexually or asexually • Growth and development • Metabolism – chemical and physical life processes • Movement and/or irritability – respond to internal/external stimuli; self-propulsion of many organisms • Cell support, protection, and storage mechanisms – cell walls, vacuoles, granules and inclusions • Transport of nutrients and waste

Structure ofabacterial cellCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or displayCell wallFimbriaeRibosomesCellmembraneapsuleSlimelayerCytoplasmicmatrixa06Mesosome5ActinChromosomePilusFlagellumInclusionfilaments(DNA)body

Structure of a bacterial cell 5 Ribosomes Cell wall Cell membrane Chromosome (DNA) Actin filaments Pilus Cytoplasmic matrix Capsule Inclusion body Flagellum Fimbriae Slime layer Mesosome Copyright © The McGraw -Hill Companies, Inc. Permission required for reproduction or display

ExternalStructures:Appendages- Two major groups of appendages: Motility - flagella and axial filaments(periplasmic flagella): Attachment or channels -fimbriae and pili? Glycocalyx - surface coating6

6 External Structures • Appendages – Two major groups of appendages: • Motility – flagella and axial filaments (periplasmic flagella) • Attachment or channels – fimbriae and pili • Glycocalyx – surface coating

Flagella: 3 parts:- Filament - long, thin, helical structure composed ofprotein flagellin-Hook-curved sheath- Basal body - stack of rings firmly anchored in cell wallCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or displayFilamentHook-Outer/Lringmembrane价价CellwallBasalPeriplasmiRod>RingsbodyspaceRingsTCell7membrane(b)(a)22nm

Hook Filament Periplasmic space L ring Cell wall Cell membrane Rod Rings Outer membrane Basal body (a) 22 nm (b) Copyright © The McGraw -Hill Companies, Inc. Permission required for reproduction or display. Rings 7 Flagella • 3 parts: – Filament – long, thin, helical structure composed of protein flagellin – Hook – curved sheath – Basal body – stack of rings firmly anchored in cell wall

FlagellaRotates 360Functions in motility of cell through environmentCopyright The McGraw-Hil Companies, Inc. Permission required for reproduction or display(a)(c)8(b)

(a) (b) (c) Copyright © The McGraw -Hill Companies, Inc. Permission required for reproduction or display. 8 Flagella • Rotates 360o • Functions in motility of cell through environment 8

9

9

FlagellarArrangementsMonotrichousCopyagtt@TheMcGraw-Hill Comparonrequredforreproducbonordspiaysingle flagellumat one endLophotrichous -small bunchesemerging fromthe same site(a)(CAmphitrichous-flagella at bothends of cellPeritrichous -flagella(b)(d)dispersed oversurface of cell18

10 Flagellar Arrangements Monotrichous – single flagellum at one end Lophotrichous – small bunches emerging from the same site Amphitrichous – flagella at both ends of cell Peritrichous – flagella dispersed over surface of cell 10