Medical Micro Bacteria

Bacterial Characteristics

Protection: Cell Membrane, Cell Wall (gram positive and gram negative), Envelope/Capsule

Movement: Flagella, Pili (solid and conjugative), Fimbria

Key roles of cell membrane and location?

Receiving information, Importing and exporting molecules, fluid enough to be flexible, moveable, and to grow.

Cell Wall’s location and role? Periplasmic is? Gram + and - ?

Location: Outside of cell membrane>periplasmic>cell wall

Cell wall helps with osmotic pressure so the bacteria don’t swell to the point of exploding

Periplasmic is a white layer outside of the cell membrane.

There are two different cell wall Gram + or Gram -

Gram is the term used as a lab technique to stain cells to be visually differentiated by colors (gram stain).

Gm+ bacteria cell wall has multiple layers

G- bacterial cell wall has a single layer

How many layers do Gram + and Gram - have? Which one is the only one to have a outer-membrane?

Gram + has multiple layers

Gram - has a single layer but consists an outer-membrane

What are cell walls made up of?

Peptidoglycan (proteins and sugars)

What are the additional components for Gram Positive Cells?

Lipoteichoic acid links: This compound helps helps secure the peptidoglycan together

Which gram bacteria also has an outer membrane?

Gram negative

Outer membrane: how is it attached to the peptidoglycan layer? What does the outer layer of it contain and what does it do?

• Attached via murein lipoprotein

• Outer layer contains the molecule lipopolysaccharide (LPS)

• LPS is an endotoxin that contributes to symptoms such as fever and septic shock?

What is a septic shock?

Our LPS recognition receptors get over whelmed/hyper-activated leads to septic shock. Via too many gram - cells in our bloodstream,

What are the other outside layers (envelope)? and role of it?

Capsule - made up of sugar matrices

S-layer: organized protein arrays

Roles: hide cell from host immune recognition, osmotic balance, make biofilm.

Flagella of Bacteria. Components and function?

Flagella is a major mean of propulsion

motility tied to taxis

Flagella components:

Basal body: Promote rotation / Hook, Filament

Can be longer than bacterium itself

Solid Pili

Solid filament

retraction / extension type of movement

tip of pilus is adhesive

short, jerky motion

Conjugative Pilus

Transfer DNA between two living bacteria