tortora • funke • case...
TRANSCRIPT
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
PowerPoint® Lecture Slide Presentation prepared by Christine L. Case
MicrobiologyB.E Pruitt & Jane J. Stein
AN INTRODUCTIONEIGHTH EDITION
TORTORA • FUNKE • CASE
Chapter 4, part AFunctional Anatomy of Prokaryotic and
Eukaryotic Cells
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Prokaryote Eukaryote
• One circular chromosome, not in a membrane
• No histones• No organelles• Peptidoglycan cell
walls• Binary fission
• Paired chromosomes, in nuclear membrane
• Histones• Organelles• Polysaccharide cell
walls• Mitotic spindle
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• Average size: 0.2 -1.0 µm × 2 - 8 µm• Basic shapes:
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• Unusual shapes• Star-shaped Stella• Square Haloarcula
• Most bacteria are monomorphic• A few are pleomorphic
Figure 4.5
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Flagella Arrangement
Figure 4.7
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Axial Filaments
Figure 4.10a
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Fimbriae and Cilia
Figure 4.11
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Peptidoglycan
Figure 4.13a
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Gram-positive cell walls Gram-negative cell walls
• Thick peptidoglycan• Teichoic acids• In acid-fast cells,
contains mycolicacid
• Thin peptidoglycan• No teichoic acids• Outer membrane
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Gram-Positive cell walls
• Teichoic acids:• Lipoteichoic acid links to plasma membrane• Wall teichoic acid links to peptidoglycan
• May regulate movement of cations• Polysaccharides provide antigenic variation
Figure 4.13b
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Gram-Negative Outer Membrane
• Lipopolysaccharides, lipoproteins, phospholipids.• Forms the periplasm between the outer membrane and
the plasma membrane.• Protection from phagocytes, complement, antibiotics.• O polysaccharide antigen, e.g., E. coli O157:H7.• Lipid A is an endotoxin.• Porins (proteins) form channels through membrane
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Gram-Negative Outer Membrane
Figure 4.13c
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Atypical Cell Walls
• Mycoplasmas• Lack cell walls• Sterols in plasma membrane
• Archaea• Wall-less, or• Walls of pseudomurein (lack NAM and D amino
acids)
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Plasma Membrane
Figure 4.14a
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Plasma Membrane
• Phospholipid bilayer• Peripheral proteins• Integral proteins• Transmembrane proteins
Figure 4.14b
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Fluid Mosaic Model
• Membrane is as viscous as olive oil.
• Proteins move to function• Phospholipids rotate and
move laterally
Figure 4.14b
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Cytoplasm
• Cytoplasm is the substance inside the plasma membrane
Figure 4.6a, b
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Nuclear Area
• Nuclear area (nucleoid)
Figure 4.6a, b