Lecture 4 4.10 Flagella and Motility 4.11 Gliding Motility 4.12 Bacterial Responses: Chemotaxis, Phototaxis, and other Taxes 4.13 Bacterial Cell Surface.

Slides:



Advertisements
Similar presentations
THE CELL AND CELLULAR ENVRIONMENT. Cell Basic structural unit of all plants and animals A membrane enclosing a thick fluid and a nucleus Specialized to.
Advertisements

Prokaryotic and Eukaryotic Cells
Functional Anatomy of Prokaryotic Cells Chapter 4.
CHARACTERISTICS OF PROKARYOTIC AND EUKARYOTIC CELLS CHAPTER 4.
Prokaryotic Cells. Prokaryotes  PLASMA MEMBRANE  CELL WALL  GLYCOCALYX  CAPSULE  SLIME LAYER  FLAGELLUM  SEX PILUS  FIMBRAE.
Typical Prokaryotic Cell. Prokaryotic Cell Structures.
PROKARYOTES ARCHAEA Cells that lack peptidoglycan, tend to live in harsh environments. Extremophiles: Methanogens: produce methane as a result of respiration.
Surface structures and inclusions of prokaryotes
Morphology of Prokaryotic Cells: Cell Shapes. Morphology of Prokaryotic Cells: terminology in practice Curved rods: –Campylobacter species –Vibrio species.
The Nucleoid Eukaryotes have a membrane-bound nucleus.
Structures external to the Cell Wall:
Flagella Slender rigid structures
Endospores – a special resistant dormant structure, formed under periods of environmental stress
Bacterial Ultrastructure
DNA Cytoplasm Cell Membrane Ribosome DNA Cytoplasm Cell Membrane Ribosome DNA Cytoplasm Cell Membrane Ribosome DNA Cytoplasm Cell Membrane Ribosome DNA.
Chapter 4 – Cell Structure and Function in Bacteria and Archaea $100 $200 $300 $400 $500 $100$100$100 $200 $300 $400 $500 Cell Size and Cell Basics Prokaryotic.
Sofronio Agustin Professor
General Microbiology (Micr300) Lecture 3 Structure and Function of Prokaryotes (Text Chapter: )
Bacteria1 Ribosome Cytoplasm Nucleoid Glycocalyx Cell wall Cytoplasmic membrane Flagellum Inclusions Prokaryotic Cell Structure Chapters 3 and 11 Eukaryotic.
Bacterial response to environment
1 Bacterial Cell Structure (continued) You are here.
Chapter 3: Microscopy and Cell Structure
Chapter 4 Cell Structure/Function. Microscopy and Cell Morphology Light Microscopy Microscopes are essential for microbiological studies. Various types.
Other Extracellular Layers Outer membrane Capsule Sheath Cell Appendages Filamentous, small: Fimbriae, Pili, & Spinae Filamentous, large: Flagella Outer.
Bacterial Motility Hugh B. Fackrell. 2 8/5/2015 Presentation Outline l Bacterial Flagella l Location l Function l Structure l Bacterial vs eukaryotic.
Morphology & Cell Biology of Bacteria (Part II) Siti Sarah Jumali (ext 2123) Room 3/14
Pili and fimbriae Flagella The bacterial endospore
Prokaryotic Cell Structure and Function
Cell Structure and Function
Global control: modulons Different operons/regulons affected by same environmental signal –Presence of glucose –Change from O 2 to anaerobic growth –Nitrogen.
Anatomy of Prokaryotes and Eukaryotes Prokaryotic Cell Structure Cell size, shapes, and arrangements Parts of a Prokaryotic Cell Glycocalyx: slime layer.
Chapter 18.  Domain Archaea  Only one kingdom: Archaebacteria ▪ Cells contain cell walls ▪ Live in extreme environments (hot, acidic, salty, no O 2.
Ch 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells
Endospores and formation of cell aggregates. Endospores - metabolically dormant stages observed in certain Gram positive bacteria A survival strategy.
Chair of Medical Biology, Microbiology, Virology, and Immunology CELL STRUCTURE OF BACTERIA. Lecturer As. Prof. O. Pokryshko.
Functional Anatomy of Prokaryotic and Eukaryotic Cells
Cell Biology Prokaryotic Cell –Small ~ 1-2µm µm Max.? Min.? –No Nucleus –Little Internal Structure –Some are Motile –Unicellular or Cluster Eukaryote.
Prokaryotes Prokaryotes are microscopic single-celled organisms. Although you cannot see them without the aid of a microscope, their combined biomass is.
Cell structure and function for microbiologists Prokaryotes Eukaryotes Both have the same types of biological molecules metabolism, protein synthesis,
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Chapter 3 The Prokaryotic Cell Structure and Function.
Ways to think about peptidoglycan 1. Bacterial Cell Structure (continued) You are here. 2.
Cell Wall of Acid Fast Contains an inner peptidoglycan layer and an outer membrane The inner peptidoglycan layer is joined to the cell.
Archaeal cell walls Can be gram-positive or gram-negative Gram-positives often have a thick surface layer Gram-negatives often have a thin layer of protein.
Figure 3.18 Peptidoglycan cable Ribitol Wall-associated protein Teichoic acid Peptidoglycan Lipoteichoic acid Cytoplasmic membrane © 2012 Pearson Education,
BIOLOGY OF BACTERIA. LAST DAY Brief introduction to bacteria, Archaebacteria, and bacterial culturing media.
The Microbial World. Tree of Life Phylogeny based on 16S ribosomal DNA. Three domains of living organisms Borderline entities –Viruses –Viroids –Prions.
Microbiology: A Systems Approach
Loose Ends on Chapters 3,5,6 SummerMicrobiology. Spore survival Dipicolinic acid and Ca++ account for 15% of the total spore mass Dipicolinic acid theoretically.
Chapter 4 Prokaryotic cell. Bacteria are prokaryotic organisms DNA is not enclosed within a membrane DNA is not associated with histone proteins ( no.
Bacterial G & R (Growth and Reproduction). Types  Asexual  Sexual  Spore Formation.
Medical Bacteriology MBIO 460 Lecture 4
Chapter 4 – Functional Anatomy of Prokaryotic and Eukaryotic Cells $100 $200 $300 $400 $500 $100$100$100 $200 $300 $400 $500 Prokaryotic Cells Cell Wall.
STRUCTURE AND FXN PT.2. CYTOPLASM Gelatinous material inside the cell membrane It is semitransparent, fluid, elastic and aqueous It contains cytosol,
Chapter 4 – Part B: Prokaryotic (bacterial) cells.
Bacteria move toward food Two bacteria capable of surviving in adverse environments DIC Attachment pili Rotate flagellum counter clockwise F plasmidFlagellumConditions.
Lecture 3 Structure and Function of Prokaryotes
Introduction to Microbiology Lecture 5
Microbiology Stephanie Lanoue
Bacterial Morphology and Structure
Advanced Biology: Bacteria Basics
Chapter 4 Prokaryote Eukaryote
Bacteriology.
Bacteria.
Bacterial Cell Structure (continued)
Structures external to the Cell Wall:
Structure of the Cell Wall
Ways to think about peptidoglycan
Chapter 4: Prokaryotic Profiles- the Bacteria and Archae
Prokaryotic Cell Structure Chapters 3 and 11
Ways to think about peptidoglycan
Presentation transcript:

Lecture Flagella and Motility 4.11 Gliding Motility 4.12 Bacterial Responses: Chemotaxis, Phototaxis, and other Taxes 4.13 Bacterial Cell Surface Structures and Cell Inclusions 4.14 Gas Vesicles 4.15 Endospores

The Flagellum 1000 H + / rotation > 40 genes involved

Flagellar motion > 40 genes involved, include regulators movement driven by propeller-like rotation can propel cells up to 60 cell lengths/s equivalent of 2.5x faster than a cheetah! expensive process: must confer strong selective advantage

Steps in Biosynthesis of Flagella

Run Types of Flagellar Arrangements

Motility in non-aqueous environments 1.polysaccharide “slime layer” —secreted slime used to pull cell along a surface 2.special proteins in the outer membrane act like feet, which are activated by inner membrane proteins resulting in “crawling”

Absence of chemical attractant Fig. 4.46a

Presence of chemical attractant Fig. 4.46b chemical gradient sensed in a temporal manner

Measuring Chemotaxis control repellent attractant

Other types of taxes phototaxis - light aerotaxis - oxygen osmotaxis - osmotic strength

Cell structures and inclusions fimbriae - aid cell adherence to surfaces pili - conjugation, attachment to host cell glycocalyx - polysaccharide layer outside cell, attachment to host cells, protection from host immune system, resistance to dessication polyhydroxyalkanoate deposits - intracellular carbon and energy store polyphosphate - intracellular reserves elemental sulfur - intracellular granules magnetosomes - intracellular magnetite crystals (iron oxide) gas vesicles - cell buoyancy

Poly-ß-hydroxybutyrate (PHB)

Poly-3-hydroxybutyrate (PHB) uCarbon and energy reserve uAccumulates intracellularly when carbon source is not limiting for growth uCan be utilized under carbon starvation conditions uBiodegradable bioplastics uProduction does not contribute greenhouse gases CH 3 —O·CH·CH 2 ·C— O [] n ~ 25,000

Gas Vesicle Proteins Fig watertight, gas-permeable structure (hydrophobic proteins)

Endospores Fig Resistant to heat, radiation, acids, drying, chemicals Do not contain RNA Dehydrated (only 10-30% H 2 O as vegetative cell)

Dipicolinic acid Fig Characteristic of endospores

How long can spores survive? See page 97, report that 250 million year old spores have been revived These spores were preserved in salt crystals of Permian age bacteria revived from brine deposits environmental contaminants prevented by steriliziation; controls for sterility

Endospore Formation triggered by sub-optimal growth conditions (heat, starvation, dessication, etc.) return to optimal conditions sees germination of spores within minutes studied by isolating mutants that do not form spores and studying at what point sporulation is blocked

Sporulation Initiated when nutrients limiting Stages determined by mutational analysis ~200 genes involved SASP = small acid-soluble spore proteins Cortex is composed of peptidoglycan Exosporium is a thin protein covering 8 h for entire process