Ppt flagella seminar

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Ppt flagella seminar

  1. 1. Bacterial Locomotor Organelles ~ Flagella
  2. 2. Flagella is a LASH or Whip like appendage , arising from Cellbody of Prokaryotic and Eukaryotic Organisms Main Function of the Flagella is Locomotion , but other than that it also functions as a Sensory Organelle. bBACTERIA
  3. 3. Motility : ● Motility -Movement ● Swarming occurs with some bacteria - Spreads across petri dishes - Proteus species is the most evident ● This motility of bacteria occur in 2 different phenomenon : ~ Phototaxis - Movement of bacteria in response to Light This phototaxis is again of 2 types - * Positive Phototaxis : Towards light * Negative Phototaxis : Away from light ~ Chemotaxis – Movement of bacteria in response to light This Chemotaxis is again of 2 types - * Positive Chemotaxis : Towards Chemical * Negative Chemotaxis : Away from Chemicals
  4. 4. Arrangement of Bacterial Flagella ● How many flagella does a bacteria have ? ● How are they arranged ? ● Do all Bacteria have flagella ? ● How does a flagella look like ? ● How does it help in movement of a bacteria ?
  5. 5. Classification of Bacteria based on arrangement of flagella . . . ● ATRICHOUS : Absence of Flagella ● MONOTRICHOUS : Presence of a Single Flagella at one end ● LOPHOTRICHOUS : Presence of “tuft” of Flagella at one end ● AMPHITRICHOUS : Presence of a single Flagella at both ends ● PERITRICHOUS : Presence of Flagella all over the cell surface .
  6. 6. Lactobacillus Vibrio Pseudomonas Spirillum E.coli
  7. 7. Examples of the bacteria based on the arrangement of flagella . . .  Atrichous : Lactobacilli ,Diptheria bacillus  Monotrichous : Vibrio cholerae  Lophotrichous : Pseudomonas  Amphitrichous : Spirillum  Peritrichous : Bacillus
  8. 8. Structure of a Flagella -Prokaryotes ● Flagellum , consists of a Basal body , Hook and a Main Filament . ● Basal Body or Basal Granule : 200 to 500 A in diameter , ● In gram -ve bacteria , basal ring has 2 sets of rings , i.e., ~ Proximal set ~ Distal set ● Each set has 2 rings,and the four rings are- M-ring , S ring , P ring , L ring .
  9. 9. Continued . . . ● The arrangement of these rings are from inside to outside . ● M-ring is anchored to Plasma membrane , and P- ring to the Peptidoglycan layer of the cell-wall. ● M-ring provides the “movement” to the flagella. ● The S-ring is the Static- ring . ● The P-ring is attached to the Peptidoglycan layer , and the L-ring to the Lipopolysaccharide layer of the membrane of the gram -ve . ● While in Gram +ve , there are only a only single set of rings ,No attachment to cell wall is seen . ● The inner rings are attached to the p.membrane.
  10. 10. Hook : ● The Hook,penetrates the cell-wall,and connects main Filament and Basal body . ● It allows the axis of the helix to point directly away from the cell. Main Filament : ● The filament consists entirely of Protein, called “Flagellin”. ● This protein is either free or consists of very low amounts of amino acid residues. ● These residues are of : - Proline,Histidine,Cysteine,Tryptophan
  11. 11. Arrangement of the Flagella
  12. 12. Flagellar Arrangement of Eukaryotic Bacteria. ● Completely different when compared to Prokaryotic flagella . ● It consists of 9 fused pairs of micro tubules that make a cylinder. ● In addition , there are 2 unfused micro-tubles present in the center of the cylinder . ● Thereby , named as 9+2 arrangement . ● Outward projection of cytoplasm.
  13. 13. Internal Structures of Eukaryotic flagellum
  14. 14. Internal Structures of flagella

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