Bacteria cells

• Capsule: A layer of material that surrounds a cell and protects it from the environment ,Desiccation, Phagocytosis, attachment to surfaces, Biofilms
• Flagella: Long, thin, whip-like structures that are used for movement.
• •Monotrichous (Mono = one)•Single polar flagellum
• •Lophotrichous (Lopho = tufted)•Two or more at one/both ends
• •Amphitrichous (Amphi = both)•Single polar flagellum at each end
• •Peritrichous (Peri = around)•Distributed over entire cell
• Flagellum Structure in Gram-negative Bacteria, Gram positive: no L ring, larger P ring
• •Chemotaxis in response to chemical stimulus (also phototaxis, aerotaxis, osmotaxis and hydrotaxis)•Positive/negative chemotaxis•Series of runs and tumbles wherein runs are extended if in direction of a chemical attractant (chemoreceptors)
• Inclusion Bodies: •Reserve deposits

  •Volutin

  •Phosphate

  •Glycogen

  •PolysaccharideLipids
• Exotoxin:

  Mostly produced by Gram positive bacteria, Produced inside bacteria as part of growth, Released
• Endotoxin:

  Constituent of cell wall of Gram negative microbes
• Exotoxins: Protein molecules

  Active (A) sub-unit

  Binding (B) sub-unit

  Mainly produced by Gram positives

  Highly specific

  Soluble in blood

  Rapid transmission

  Rapid onset of symptoms
• Peptidoglycan:

  • The backbone of peptidoglycan consists of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) molecules linked together in a linear chain.
• Peptidoglycan:

  Attached to the NAM molecules are short peptide chains that extend from each sugar unit. These peptide chains vary in length and composition depending on the bacterial species. Typically, they consist of a few amino acids, such as L-alanine, D-alanine, meso-diaminopimelic acid (DAP), and D-glutamic acid. These peptide chains are responsible for cross-linking adjacent strands of peptidoglycan, providing strength to the cell wall.
• Peptidoglycan: The peptide chains extending from the NAM molecules cross-link with tetrapeptide chains, forming a three-dimensional network.
• Some bacteria have additional modifications, which effect the composition of peptidoglycan contributing to the different levels of antibiotic resistance.