PLTW MI 1.2.1 - Antibiotic Therapy

Antibiotics

A substance produced or derived from a microorganism and able in dilute solution to inhibit or kill another microorganism

Nucleoid

The DNA-containing area of a bacterial cell

-Contains essential genes

Plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

Ribosomes

Synthesize protein

Cell wall

A stiff, protective barrier outside the cell membrane and inside capsule

Plasma membrane

flexible, selectively permeable boundary that contains cytoplasm (innermost layer)

Capsule

Tough layer outside the cell wall (outermost layer)

Flagella

Facilitates cell movement

Pili

(Singular: pilus) Allows cell to attach to specific surfaces & offers protection from human immune responses

Endotoxins

Part of outer membrane of the cell wall of Gram-negative bacteria; toxic substances released when bacteria rupture

Gram-negative bacteria

-Stains pink

-Multilayered cell wall

1) Outer layer: Outer membrane (phospholipid-lipopolysaccharide)

2) Middle layer (suspended in periplasm): thin peptidoglycan sheet

3) Inner layer: plasma membrane

Gram-positive bacteria

-Stains purple

-Thick peptidoglycan layer overlying plasma membrane

β - Lactam antibiotics

aka: Penicillins

-Prevent cell from building its cell wall

-Disrupts the enzyme "transpeptidase" which carries out the peptidoglycan cross-linking process

-Leaves holes in cell wall, causing cell to rupture

Tetracyclines

Inhibits protein synthesis so bacteria can't make things it needs to live

-Binds to ribosomes so tRNA can't bind to the RNA-ribosome complex

Fluoroquinolones

Inhibit the enzyme DNA gyrase so bacteria cannot synthesize DNA

Sulfa antibiotics

aka: sulfonamids

-Stops production of folate (vital nutrient) by inhibiting DHPS enzyme

What type of bacteria is Neisseria meningitidis?

Gram negative

-Diplococcus