chapter 27 presentation
TRANSCRIPT
![Page 1: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/1.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
PowerPoint® Lecture Presentations for
Biology Eighth Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp
Chapter 27Chapter 27
Bacteria and Archaea
![Page 2: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/2.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Prokaryotes thrive almost everywhere, including places too acidic, salty, cold, or hot for most other organisms
• Most prokaryotes are microscopic, but what they lack in size they make up for in numbers
• There are more in a handful of fertile soil than the number of people who have ever lived
Overview: Masters of Adaptation
![Page 3: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/3.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• They have an astonishing genetic diversity
• Prokaryotes are divided into two domains: bacteria and archaea
Video: TubewormsVideo: Tubeworms
![Page 4: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/4.jpg)
Fig. 27-1
![Page 5: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/5.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 27.1: Structural and functional adaptations contribute to prokaryotic success
• Most prokaryotes are unicellular, although some species form colonies
• Most prokaryotic cells are 0.5–5 µm, much smaller than the 10–100 µm of many eukaryotic cells
• Prokaryotic cells have a variety of shapes
• The three most common shapes are spheres (cocci), rods (bacilli), and spirals
![Page 6: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/6.jpg)
Fig. 27-2
(a) Spherical (cocci)
1 µm
(b) Rod-shaped (bacilli)
2 µm
(c) Spiral
5 µm
![Page 7: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/7.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cell-Surface Structures
• An important feature of nearly all prokaryotic cells is their cell wall, which maintains cell shape, provides physical protection, and prevents the cell from bursting in a hypotonic environment
• Eukaryote cell walls are made of cellulose or chitin
• Bacterial cell walls contain peptidoglycan, a network of sugar polymers cross-linked by polypeptides
![Page 8: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/8.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Archaea contain polysaccharides and proteins but lack peptidoglycan
• Using the Gram stain, scientists classify many bacterial species into Gram-positive and Gram-negative groups based on cell wall composition
• Gram-negative bacteria have less peptidoglycan and an outer membrane that can be toxic, and they are more likely to be antibiotic resistant
![Page 9: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/9.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Many antibiotics target peptidoglycan and damage bacterial cell walls
![Page 10: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/10.jpg)
Fig. 27-3
Cellwall
Peptidoglycanlayer
Plasma membrane
Protein
Gram-positivebacteria
(a) Gram-positive: peptidoglycan traps crystal violet.
Gram-negativebacteria
(b) Gram-negative: crystal violet is easily rinsed away, revealing red dye.
20 µm
Cellwall
Plasma membrane
Protein
Carbohydrate portionof lipopolysaccharide
Outermembrane
Peptidoglycanlayer
![Page 11: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/11.jpg)
Fig. 27-3a
Cellwall
Peptidoglycanlayer
Plasma membrane
Protein
(a) Gram-positive: peptidoglycan traps crystal violet.
![Page 12: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/12.jpg)
Fig. 27-3b
Cellwall Peptidoglycan
layerPlasma membrane
Protein
(b) Gram-negative: crystal violet is easily rinsed away, revealing red dye.
Outermembrane
Carbohydrate portionof lipopolysaccharide
![Page 13: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/13.jpg)
Fig. 27-3c
Gram-positivebacteria
Gram-negativebacteria
20 µm
![Page 14: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/14.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• A polysaccharide or protein layer called a capsule covers many prokaryotes
![Page 15: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/15.jpg)
Fig. 27-4
Capsule
200 nm
![Page 16: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/16.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Some prokaryotes have fimbriae (also called attachment pili), which allow them to stick to their substrate or other individuals in a colony
• Sex pili are longer than fimbriae and allow prokaryotes to exchange DNA
![Page 17: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/17.jpg)
Fig. 27-5
Fimbriae
200 nm
![Page 18: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/18.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Motility
• Most motile bacteria propel themselves by flagella that are structurally and functionally different from eukaryotic flagella
• In a heterogeneous environment, many bacteria exhibit taxis, the ability to move toward or away from certain stimuli
Video: Prokaryotic Flagella (Video: Prokaryotic Flagella (Salmonella typhimuriumSalmonella typhimurium))
![Page 19: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/19.jpg)
Fig. 27-6
Flagellum
Filament
Hook
Basal apparatus
Cell wall
Plasmamembrane
50 nm
![Page 20: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/20.jpg)
Fig. 27-6a
Cell wall
Filament
Hook
Basal apparatus
Plasmamembrane
![Page 21: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/21.jpg)
Fig. 27-6b
Prokaryotic flagellum (TEM)
50 nm
![Page 22: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/22.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Internal and Genomic Organization
• Prokaryotic cells usually lack complex compartmentalization
• Some prokaryotes do have specialized membranes that perform metabolic functions
![Page 23: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/23.jpg)
Fig. 27-7
(a) Aerobic prokaryote (b) Photosynthetic prokaryote
Thylakoidmembranes
Respiratorymembrane
0.2 µm 1 µm
![Page 24: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/24.jpg)
Fig. 27-7a
(a) Aerobic prokaryote
Respiratorymembrane
0.2 µm
![Page 25: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/25.jpg)
Fig. 27-7b
(b) Photosynthetic prokaryote
Thylakoidmembranes
1 µm
![Page 26: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/26.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The prokaryotic genome has less DNA than the eukaryotic genome
• Most of the genome consists of a circular chromosome
• Some species of bacteria also have smaller rings of DNA called plasmids
![Page 27: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/27.jpg)
Fig. 27-8
Chromosome Plasmids
1 µm
![Page 28: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/28.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The typical prokaryotic genome is a ring of DNA that is not surrounded by a membrane and that is located in a nucleoid region
![Page 29: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/29.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Reproduction and Adaptation
• Prokaryotes reproduce quickly by binary fission and can divide every 1–3 hours
• Many prokaryotes form metabolically inactive endospores, which can remain viable in harsh conditions for centuries
![Page 30: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/30.jpg)
Fig. 27-9
Endospore
0.3 µm
![Page 31: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/31.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Prokaryotes can evolve rapidly because of their short generation times
![Page 32: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/32.jpg)
Fig. 27-10EXPERIMENT
RESULTS
Daily serial transfer
0.1 mL(population sample)
Old tube(discardedaftertransfer)
New tube(9.9 mLgrowthmedium)
Fit
nes
s re
lati
veto
an
ces
tor
Generation0 5,000 10,000 15,000 20,000
1.0
1.2
1.4
1.6
1.8
![Page 33: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/33.jpg)
Fig. 27-10a
EXPERIMENT
Daily serial transfer
0.1 mL(population sample)
Old tube(discardedaftertransfer)
New tube(9.9 mLgrowthmedium)
![Page 34: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/34.jpg)
Fig. 27-10b
RESULTSF
itn
ess
rela
tive
to a
nce
sto
r
Generation0 5,000 10,000 15,000 20,000
1.0
1.2
1.4
1.6
1.8
![Page 35: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/35.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Prokaryotes have considerable genetic variation
• Three factors contribute to this genetic diversity:
– Rapid reproduction
– Mutation
– Genetic recombination
Concept 27.2: Rapid reproduction, mutation, and genetic recombination promote genetic diversity in prokaryotes
![Page 36: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/36.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Rapid Reproduction and Mutation
• Prokaryotes reproduce by binary fission, and offspring cells are generally identical
• Mutation rates during binary fission are low, but because of rapid reproduction, mutations can accumulate rapidly in a population
• High diversity from mutations allows for rapid evolution
![Page 37: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/37.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Genetic Recombination
• Additional diversity arises from genetic recombination
• Prokaryotic DNA from different individuals can be brought together by transformation, transduction, and conjugation
![Page 38: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/38.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Transformation and Transduction
• A prokaryotic cell can take up and incorporate foreign DNA from the surrounding environment in a process called transformation
• Transduction is the movement of genes between bacteria by bacteriophages (viruses that infect bacteria)
![Page 39: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/39.jpg)
Fig. 27-11-1
Donorcell
A+ B+
A+ B+
Phage DNA
![Page 40: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/40.jpg)
Fig. 27-11-2
A+
Donorcell
A+ B+
A+ B+
Phage DNA
![Page 41: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/41.jpg)
Fig. 27-11-3
Recipientcell
B–
A+
A–
Recombination
A+
Donorcell
A+ B+
A+ B+
Phage DNA
![Page 42: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/42.jpg)
Fig. 27-11-4
Recombinant cell
Recipientcell
A+ B–
B–
A+
A–
Recombination
A+
Donorcell
A+ B+
A+ B+
Phage DNA
![Page 43: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/43.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Conjugation and Plasmids
• Conjugation is the process where genetic material is transferred between bacterial cells
• Sex pili allow cells to connect and pull together for DNA transfer
• A piece of DNA called the F factor is required for the production of sex pili
• The F factor can exist as a separate plasmid or as DNA within the bacterial chromosome
![Page 44: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/44.jpg)
Fig. 27-12
Sex pilus 1 µm
![Page 45: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/45.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The F Factor as a Plasmid
• Cells containing the F plasmid function as DNA donors during conjugation
• Cells without the F factor function as DNA recipients during conjugation
• The F factor is transferable during conjugation
![Page 46: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/46.jpg)
Fig. 27-13
F plasmid
F+ cell
F– cell
Matingbridge
Bacterial chromosome
Bacterialchromosome
(a) Conjugation and transfer of an F plasmid
F+ cell
F+ cell
F– cell
(b) Conjugation and transfer of part of an Hfr bacterial chromosome
F factor
Hfr cell A+A+
A+
A+
A+A– A– A–
A– A+
RecombinantF– bacterium
![Page 47: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/47.jpg)
Fig. 27-13-1
F plasmid
F+ cell
F– cell
Matingbridge
Bacterial chromosome
Bacterialchromosome
(a) Conjugation and transfer of an F plasmid
![Page 48: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/48.jpg)
Fig. 27-13-2
F plasmid
F+ cell
F– cell
Matingbridge
Bacterial chromosome
Bacterialchromosome
(a) Conjugation and transfer of an F plasmid
![Page 49: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/49.jpg)
Fig. 27-13-3
F plasmid
F+ cell
F– cell
Matingbridge
Bacterial chromosome
Bacterialchromosome
(a) Conjugation and transfer of an F plasmid
F+ cell
F+ cell
![Page 50: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/50.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The F Factor in the Chromosome
• A cell with the F factor built into its chromosomes functions as a donor during conjugation
• The recipient becomes a recombinant bacterium, with DNA from two different cells
• It is assumed that horizontal gene transfer is also important in archaea
![Page 51: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/51.jpg)
Fig. 27-13-4
F factor
Hfr cell
(b) Conjugation and transfer of part of an Hfr bacterial chromosome
A+
A–
F– cell
A+
A+
A–
![Page 52: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/52.jpg)
Fig. 27-13-5
F factor
Hfr cell
(b) Conjugation and transfer of part of an Hfr bacterial chromosome
A+
A–
F– cell
A+
A+
A–
A+
A+ A–
![Page 53: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/53.jpg)
Fig. 27-13-6
F factor
Hfr cell
(b) Conjugation and transfer of part of an Hfr bacterial chromosome
A+
A–
F– cell
A+
A+
A–
A+
A+ A–
RecombinantF– bacterium
A– A+
![Page 54: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/54.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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
![Page 55: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/55.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 27.3: Diverse nutritional and metabolic adaptations have evolved in prokaryotes
• Phototrophs obtain energy from light
• Chemotrophs obtain energy from chemicals
• Autotrophs require CO2 as a carbon source
• Heterotrophs require an organic nutrient to make organic compounds
• These factors can be combined to give the four major modes of nutrition: photoautotrophy, chemoautotrophy, photoheterotrophy, and chemoheterotrophy
![Page 56: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/56.jpg)
Table 27-1
![Page 57: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/57.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Role of Oxygen in Metabolism
• Prokaryotic metabolism varies with respect to O2:
– Obligate aerobes require O2 for cellular respiration
– Obligate anaerobes are poisoned by O2 and use fermentation or anaerobic respiration
– Facultative anaerobes can survive with or without O2
![Page 58: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/58.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nitrogen Metabolism
• Prokaryotes can metabolize nitrogen in a variety of ways
• In nitrogen fixation, some prokaryotes convert atmospheric nitrogen (N2) to ammonia (NH3)
![Page 59: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/59.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Metabolic Cooperation
• Cooperation between prokaryotes allows them to use environmental resources they could not use as individual cells
• In the cyanobacterium Anabaena, photosynthetic cells and nitrogen-fixing cells called heterocytes exchange metabolic products
Video: Cyanobacteria (Video: Cyanobacteria (OscillatoriaOscillatoria))
![Page 60: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/60.jpg)
Fig. 27-14
Photosyntheticcells
Heterocyte
20 µm
![Page 61: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/61.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• In some prokaryotic species, metabolic cooperation occurs in surface-coating colonies called biofilms
![Page 62: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/62.jpg)
Fig. 27-15
1 µ
m
![Page 63: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/63.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 27.4: Molecular systematics is illuminating prokaryotic phylogeny
• Until the late 20th century, systematists based prokaryotic taxonomy on phenotypic criteria
• Applying molecular systematics to the investigation of prokaryotic phylogeny has produced dramatic results
![Page 64: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/64.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Lessons from Molecular Systematics
• Molecular systematics is leading to a phylogenetic classification of prokaryotes
• It allows systematists to identify major new clades
![Page 65: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/65.jpg)
Fig. 27-16
UNIVERSALANCESTOR
Eukaryotes
Korarcheotes
Euryarchaeotes
Crenarchaeotes
Nanoarchaeotes
Proteobacteria
Chlamydias
Spirochetes
Cyanobacteria
Gram-positivebacteria
Do
main
Eu
karyaD
om
ain A
rchaea
Do
main
Bacteria
![Page 66: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/66.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The use of polymerase chain reaction (PCR) has allowed for more rapid sequencing of prokaryote genomes
• A handful of soil many contain 10,000 prokaryotic species
• Horizontal gene transfer between prokaryotes obscures the root of the tree of life
![Page 67: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/67.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Archaea
• Archaea share certain traits with bacteria and other traits with eukaryotes
![Page 68: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/68.jpg)
Fig. 27-UN1
Eukarya
Archaea
Bacteria
![Page 69: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/69.jpg)
Table 27-2
![Page 70: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/70.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Some archaea live in extreme environments and are called extremophiles
• Extreme halophiles live in highly saline environments
• Extreme thermophiles thrive in very hot environments
![Page 71: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/71.jpg)
Fig. 27-17
![Page 72: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/72.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Methanogens live in swamps and marshes and produce methane as a waste product
• Methanogens are strict anaerobes and are poisoned by O2
• In recent years, genetic prospecting has revealed many new groups of archaea
• Some of these may offer clues to the early evolution of life on Earth
![Page 73: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/73.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Bacteria
• Bacteria include the vast majority of prokaryotes of which most people are aware
• Diverse nutritional types are scattered among the major groups of bacteria
![Page 74: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/74.jpg)
Fig. 27-UN2
Eukarya
Archaea
Bacteria
![Page 75: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/75.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Proteobacteria
• These gram-negative bacteria include photoautotrophs, chemoautotrophs, and heterotrophs
• Some are anaerobic, and others aerobic
![Page 76: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/76.jpg)
Fig. 27-18a
Alpha
Beta
Gamma
Delta
Epsilon
Proteobacteria
Subgroup: Beta Proteobacteria
Nitrosomonas (colorized TEM)
1 µ
m
Subgroup: Delta Proteobacteria
10 µ
m
Fruiting bodies ofChondromyces crocatus, amyxobacterium (SEM)
Bdellovibrio bacteriophorusattacking a larger bacterium(colorized TEM)
5 µ
m
Helicobacter pylori (colorized TEM)
2 µ
m0.
5 µ
m
Subgroup: Epsilon Proteobacteria
B. bacteriophorus
Thiomargarita namibiensiscontaining sulfur wastes (LM)
Subgroup: Gamma Proteobacteria
Subgroup: Alpha Proteobacteria
Rhizobium (arrows) inside aroot cell of a legume (TEM)
2.5
µm
![Page 77: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/77.jpg)
Fig. 27-18b
Alpha
Beta
Gamma
Delta
Epsilon
Proteobacteria
![Page 78: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/78.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Subgroup: Alpha Proteobacteria
• Many species are closely associated with eukaryotic hosts
• Scientists hypothesize that mitochondria evolved from aerobic alpha proteobacteria through endosymbiosis
![Page 79: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/79.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Example: Rhizobium, which forms root nodules in legumes and fixes atmospheric N2
• Example: Agrobacterium, which produces tumors in plants and is used in genetic engineering
![Page 80: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/80.jpg)
Fig. 27-18c
Rhizobium (arrows) inside a rootcell of a legume (TEM)
2.5
µm
![Page 81: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/81.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Subgroup: Beta Proteobacteria
• Example: the soil bacterium Nitrosomonas, which converts NH4
+ to NO2–
![Page 82: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/82.jpg)
Fig. 27-18d
Nitrosomonas (colorized TEM)
1 µ
m
![Page 83: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/83.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Subgroup: Gamma Proteobacteria
• Examples include sulfur bacteria such as Chromatium and pathogens such as Legionella, Salmonella, and Vibrio cholerae
• Escherichia coli resides in the intestines of many mammals and is not normally pathogenic
![Page 84: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/84.jpg)
Fig. 27-18e
Thiomargarita namibiensiscontaining sulfur wastes (LM)
0.5
µm
![Page 85: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/85.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Subgroup: Delta Proteobacteria
• Example: the slime-secreting myxobacteria
![Page 86: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/86.jpg)
Fig. 27-18f
Fruiting bodies ofChondromyces crocatus, amyxobacterium (SEM)
10 µ
m
![Page 87: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/87.jpg)
Fig. 27-18g
Bdellovibrio bacteriophorusattacking a larger bacterium(colorized TEM)
5 µ
m
B. bacteriophorus
![Page 88: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/88.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Subgroup: Epsilon Proteobacteria
• This group contains many pathogens including Campylobacter, which causes blood poisoning, and Helicobacter pylori, which causes stomach ulcers
![Page 89: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/89.jpg)
Fig. 27-18h
Helicobacter pylori (colorized TEM)
2 µ
m
![Page 90: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/90.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Chlamydias
• These bacteria are parasites that live within animal cells
• Chlamydia trachomatis causes blindness and nongonococcal urethritis by sexual transmission
![Page 91: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/91.jpg)
Fig. 27-18i
CHLAMYDIAS
2.5
µm
CYANOBACTERIA
SPIROCHETES
GRAM-POSITIVE BACTERIA
Chlamydia (arrows) inside ananimal cell (colorized TEM)
Leptospira, a spirochete(colorized TEM)
5 µ
m
50
µm
Two species of Oscillatoria,filamentous cyanobacteria (LM)
Streptomyces, the source ofmany antibiotics (colorized SEM)
5 µ
m
1 µ
m
Hundreds of mycoplasmascovering a human fibroblastcell (colorized SEM)
![Page 92: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/92.jpg)
Fig. 27-18j
2.5
µm
Chlamydia (arrows) inside ananimal cell (colorized TEM)
![Page 93: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/93.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Spirochetes
• These bacteria are helical heterotrophs
• Some, such as Treponema pallidum, which causes syphilis, and Borrelia burgdorferi, which causes Lyme disease, are parasites
![Page 94: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/94.jpg)
Fig. 27-18k
Leptospira, a spirochete(colorized TEM)
5 µ
m
![Page 95: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/95.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cyanobacteria
• These are photoautotrophs that generate O2
• Plant chloroplasts likely evolved from cyanobacteria by the process of endosymbiosis
![Page 96: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/96.jpg)
Fig. 27-18l
50 µ
m
Two species of Oscillatoria,filamentous cyanobacteria (LM)
![Page 97: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/97.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Gram-Positive Bacteria
• Gram-positive bacteria include
– Actinomycetes, which decompose soil
– Bacillus anthracis, the cause of anthrax
– Clostridium botulinum, the cause of botulism
– Some Staphylococcus and Streptococcus, which can be pathogenic
– Mycoplasms, the smallest known cells
![Page 98: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/98.jpg)
Fig. 27-18m
Streptomyces, the source of manyantibiotics (colorized SEM)
5 µ
m
![Page 99: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/99.jpg)
Fig. 27-18n
1 µ
m
Hundreds of mycoplasmascovering a human fibroblastcell (colorized SEM)
![Page 100: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/100.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 27.5: Prokaryotes play crucial roles in the biosphere
• Prokaryotes are so important to the biosphere that if they were to disappear the prospects for any other life surviving would be dim
![Page 101: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/101.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Chemical Cycling
• Prokaryotes play a major role in the recycling of chemical elements between the living and nonliving components of ecosystems
• Chemoheterotrophic prokaryotes function as decomposers, breaking down corpses, dead vegetation, and waste products
• Nitrogen-fixing prokaryotes add usable nitrogen to the environment
![Page 102: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/102.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Prokaryotes can sometimes increase the availability of nitrogen, phosphorus, and potassium for plant growth
• Prokaryotes can also “immobilize” or decrease the availability of nutrients
![Page 103: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/103.jpg)
Fig. 27-19
Nobacteria
Strain 1 Strain 2 Strain 3
Soil treatment
Up
take
of
K b
y p
lan
ts (
mg
)
0
0.2
0.4
0.6
0.8
1.0
![Page 104: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/104.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Ecological Interactions
• Symbiosis is an ecological relationship in which two species live in close contact: a larger host and smaller symbiont
• Prokaryotes often form symbiotic relationships with larger organisms
![Page 105: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/105.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• In mutualism, both symbiotic organisms benefit
• In commensalism, one organism benefits while neither harming nor helping the other in any significant way
• In parasitism, an organism called a parasite harms but does not kill its host
• Parasites that cause disease are called pathogens
![Page 106: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/106.jpg)
Fig. 27-20
![Page 107: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/107.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 27.6: Prokaryotes have both harmful and beneficial impacts on humans
• Some prokaryotes are human pathogens, but others have positive interactions with humans
![Page 108: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/108.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Pathogenic Prokaryotes
• Prokaryotes cause about half of all human diseases
• Lyme disease is an example
![Page 109: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/109.jpg)
Fig. 27-21
5 µm
![Page 110: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/110.jpg)
Fig. 27-21a
Deer tick
![Page 111: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/111.jpg)
5 µm
Fig. 27-21b
Borrelia burgdorferi (SEM)
5 µm
![Page 112: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/112.jpg)
Fig. 27-21c
Lyme disease rash
![Page 113: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/113.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Pathogenic prokaryotes typically cause disease by releasing exotoxins or endotoxins
• Exotoxins cause disease even if the prokaryotes that produce them are not present
• Endotoxins are released only when bacteria die and their cell walls break down
• Many pathogenic bacteria are potential weapons of bioterrorism
![Page 114: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/114.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Prokaryotes in Research and Technology
• Experiments using prokaryotes have led to important advances in DNA technology
• Prokaryotes are the principal agents in bioremediation, the use of organisms to remove pollutants from the environment
![Page 115: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/115.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Some other uses of prokaryotes:
– Recovery of metals from ores
– Synthesis of vitamins
– Production of antibiotics, hormones, and other products
![Page 116: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/116.jpg)
Fig. 27-22
(a)
(b)
(c)
![Page 117: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/117.jpg)
Fig. 27-22a
(a)
![Page 118: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/118.jpg)
Fig. 27-22b
(b)
![Page 119: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/119.jpg)
Fig. 27-22c
(c)
![Page 120: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/120.jpg)
Fig. 27-UN3
Fimbriae
Capsule
Cell wall
Circular chromosome
Internalorganization
Flagella
Sex pilus
![Page 121: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/121.jpg)
Fig. 27-UN4
![Page 122: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/122.jpg)
Fig. 27-UN5
![Page 123: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/123.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
You should now be able to:
1. Distinguish between the cell walls of gram-positive and gram-negative bacteria
2. State the function of the following features: capsule, fimbriae, sex pilus, nucleoid, plasmid, and endospore
3. Explain how R plasmids confer antibiotic resistance on bacteria
![Page 124: Chapter 27 Presentation](https://reader035.vdocuments.site/reader035/viewer/2022062220/55507f91b4c9051e5b8b4580/html5/thumbnails/124.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
4. 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