1. Structure Internal to the cell wall
   1. Endospores
      1. Resting cells
      2. Highly durable dehydrated with thick walls and additional layers
      3. Formed when essential nutrients are depleted
      4. Survive extreme heat, lack of water, toxic chemicals and radiation
      5. Formed internal too the bacterial cell membrane
      6. Problem in food industry - food poisoning of Clostridium Botulinum
      7. Contains
         1. DNA, RNA
         2. Ribosomes
         3. Enzymes
         4. Organic acid (Dipicolinic acid)
         5. Large number of Calcium ions
      8. Germination
         1. Triggered by physical or chemical damage to endospore's coat
         2. Endospore enzyme break down the surrounding layers
         3. Water enters
         4. Metabolism Resumes
   2. Plasma(cytoplasic) membrane
      1. Lying inside the cell wall
      2. Enclosing the cytoplasm
      3. Consist of
         1. Phospholipids
            1. Arranged in two parallel rows called lipid bilayer
            2. Contain
            3. Polar Head (Hydrophilic Phosphate group and glycerol)
            4. Non-polar tails (Hydrophobic Fatty acids)
         2. Proteins
            1. Periferal Proteins
            2. Lie at the inner or outer surface of the membrane
            3. Easily removed by mild treatment
            4. Functions
            5. Enzymes for chemical reactions
            6. Scaffold for support
            7. Mediators of changes in membrane shape during movements
            8. Integral Proteins
            9. Penetrate the membrane completely
            10. Also called Transmembrane Proteins
            11. Removed only after disrupting the lipid bilayer
            12. Channels with pores to allow substances enter or exit the cell
         3. Eukaryotes also contain carbohydrates and sterols
            1. Glycoproteinss (carbohydrate + Protein)
            2. Glycolipids (Carbohydrate + Lipid)
      4. Phospholipid and proteins are not static but move quite freely within the membrane surface
      5. Fluid Mosaic Model
         1. Provides flexibility to the membrane
         2. self-sealing bilayer
         3. Breaks and tear will heal themselves
      6. Functions
         1. as a selective barrier through which materials enter and exit the cell
            1. Selective permeability
            2. Molecules with easy access
            3. Small Molecules
            4. Substances that dissolve in Lipids
         2. For Breakdown of nutrients
         3. Production of energy
            1. For photosynthetic bacteria, Pigments and enzymes for photosynthesis are found in folding of plasma membrane which extend into the cytoplasm. (Chromatophores or Thylakoids)
            2. Floating Topic
   3. Cytoplasm
      1. Substances of the cell inside the plasma membrane
      2. 80% water and primarily contains proteins (enzymes), Carbohydrates, Lipids and etc.
      3. Major structures
         1. Nuclear area
         2. Ribosome
         3. Inclusions
   4. Nuclear Area
      1. Also known as nucleoid
      2. Single, long, continuous and circularly arranged thread of double stranded DNA(Bacterial Chromosome) - Carry cell's genetic information
      3. Not surrounded by nuclear envelope (Membrane)
      4. Do not have histones
      5. May also contain small circular double stranded DNA molecules - Plasmids (extrachromosomal genetic elements)
      6. Plasmids: Contain gene not crucial for survival but an advantage
   5. Ribosomes
      1. Sites of Protein synthesis
      2. two Subunits
         1. Small subunit + Large subunit = complete 70s ribosome
   6. Inclusions
      1. Reserve deposits
      2. can serve as a basis of identification
      3. types
         1. Metachromatic granules
            1. Stained red with methylene blue
            2. Collectively known as volutin
            3. Contain polyphosphate for ATP synthesis
            4. Found in Algae, Fungi and Protozoa
            5. Special characteristics of CORYNEBACTERIUM DIPHTHERIA
         2. Polysaccharide granules
            1. Consist glycogen or starch
         3. Lipid inclusions
            1. For Lipid storage
         4. Sulfur granules
            1. Present in Sulfur Bacteria
            2. Sulfur as Energy reserve
         5. Carboxysomes
            1. Contain enzyme ribose 1.5- diphosphate carboxylase
            2. Present in Photosynthetic and nitrifying Bacteria
         6. Gas vacuoles
            1. To maintain buoyancy so the cells can remain at the desired depth in the water
            2. Found in aquatic prokaryote
         7. Magnetosomes
            1. Inclusion of Iron Oxide
            2. Act like Magnets
            3. Can decompose hydrogen peroxide
2. Movement of Materials across the Membrane
   1. Active Transport
      1. From low concentration to high concentration (with Expenditure of energy)
   2. Passive Transport
      1. From High concentration to low concentration (without Expenditure of Energy)
         1. Simple diffusion
         2. Facilitated diffusion
         3. Osmosis
            1. Isotonic
            2. Hypotonic
            3. Hypertonic
3. General Characteristics
   1. Mostly Unicellular, only a few have multicellular stages in their life cycle
   2. Include Bacteria and Archea (Almost Similar)
   3. Diameter: From 0.2 - 2.0 um
   4. Length: 2-8 um
   5. Various shapes
4. The cell wall
   1. General Composition and Characteristics
      1. Made of a network of peptidoglycan
      2. Peptidoglycan consist of repeating disaccharides made of
         1. N-acetylglucosamine (NAG)
         2. N-acetylmuramic acid (NAM)
      3. Alternating NAM and NAG are linked in rows of 10 to 65 sugars - Carbohydrate Backbone
      4. Adjacent rows are linked by polypeptides(peptide portion of peptidoglycan)
   2. Functions
      1. Responsible for shape of cell
      2. Prevent bacterial cells from repturing due to changes in pressure
      3. The point of anchorage for flagella
      4. May contain antigen if bacteria is infectious
   3. Gram Positive cell wall
      1. Many layers of peptidoglycan
      2. Contains teichoic acid
         1. Lipoteichoic acid (spans the PG layer and linked to the membrane)
         2. wall teichoic acid (links the PG layer)
         3. Functions
            1. It's -ve charge bind and regulate movement of cations
            2. Strengthen structure of cell wall
            3. Provides the wall's antigenic specificity
   4. Gram Negative cell wall
      1. One or very few layers of PG and outer membrane
      2. No teichoic acid
      3. PG is bonded to lipoproteins in OM and in the Periplasm
      4. OM consists of
         1. Lipopolysaccharide (LPS)
         2. Lipoproteins
         3. Phospholipids
      5. Functions of OM
         1. it's -ve charge helps cell to avoid phagocytosis and complement system
         2. Provides barrier to certain antibiotics (penicilin), digestive enzymes (lysozyme), detergents and etc
      6. Porins: Provide permeability (passage for small molecules)
      7. Components of LPS
         1. Components of LPS: Polysaccharide portion -O polysaccharide
         2. Lipid portion: Lipid A
   5. Atypical cell wall
      1. certain types of prokaryotes have no cell wall
      2. With special content of cell wall
5. Structures external to the cell wall
   1. Glycocalyx
      1. A coating secreted by the Bacteria
      2. Composed of polysaccharide and/or Polypeptide
      3. Chemical composition varies with species
      4. Different Terms depending on structure
         1. Gelatinous - Glycocalyx
         2. Organized and firmly attached to the cell wall - Capsule
         3. Unorganized and loosly attached - Slime layer
      5. Functions
         1. Capsule
            1. Contributes to Bacterial virulence
            2. Protect pathogenic bacteria from Phagocytosis by the Host cells
         2. Glycocalyx
            1. Attachment to surface
            2. Protect against dehydration
            3. Inhibit movement of nutrient out of cells
            4. Source of nutrient
   2. Flagella
      1. Singular: Flagellum
      2. Lon filamentous appendages that propel bacteria (motility)
      3. Bacteria lack flagella are referred as Atrichous
      4. Different arrangements of flagella
         1. Monotrichous (Single polar flagellum)
         2. Amphitrichous (Single flagellum at each end)
         3. Lophotrichous (Several flagella at both ends)
         4. Peritrichous (Flagella distributed over the entire cell)
      5. Basic structure (3 main parts)
         1. Filament
            1. Several Protein Flagellin chains form a helix around a hollow core
            2. In most Bacteria filaments are not covered by membrane
         2. Hook (flexible coupling between filament and basal body)
         3. Basal body
            1. Acts as a Rotary Molecular Motor
            2. Rotation (Clockwise or anticlockwise) results in movement
            3. A small central rod inserted into series of rings
            4. Inner rings: MS ring & C ring Outer rings: L ring & P ring
            5. Different arrangement in G(+) and G(-) bacteria
   3. Axial Filaments
      1. Present in spirochetes
      2. Also known as Endoflagella
      3. Bundles of fibrils arise at the ends of the cell beneath an outer sheath and apiral around the cell -> Cockscrew Movement
   4. Fimbriae and Pili
      1. Shorter,Straighter and Thinner than flagella
         1. Fimbriae
            1. Singular: Fimbria
            2. Occur at the poles or distributed over the entire surface
            3. Numbers: a few to several hundred per cell
            4. For attachment
         2. Pili
            1. Singular: Pilus
            2. Longer than fimbriae
            3. one or two per cell
            4. For transfer of DNA