Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
28 Cards in this Set
- Front
- Back
|
Archae group of bacteria
|
Ancient bacteria, oxidize sulfur for energy.
|
|
|
Bacteria
|
Prokaryote cells with no nucleus
|
|
|
Eubacteria group of bacteria
11 characteristics |
Most widespread group living today. Features:
Cell Wall Anatomy Colony morphology Gram Stain Capsule Glycocalyx Endospores Toxins Flagella Generation Time Pili |
|
|
Cell Wall of bacteria
|
composed of peptidoglycan
|
|
|
Peptidoglycan
|
Polysaccharide forming the cell wall of bacteria.
|
|
|
Anatomy of bacteria
|
Coccus
Bacillus Spirillum |
|
|
Coccus shape and subtypes with examples
|
round
--diplococcus has two, as gonorrhea --staphylococcus or 'staph', cluster of cocci, as in skin infections --streptococcus or 'strep', chain of cocci, as in strep throat |
|
|
Bacillus shape and example
|
Rod-shaped, as anthrax
|
|
|
Spirillum shape (spirochete) and example
|
Spiral shaped, as syphilis
|
|
|
Colony morphology
|
appearance when millions of bacteria grow together on a nutrient agar plate. Each species is distinctive.
|
|
|
Gram Stain, positive and negative
|
Determines width of cell wall.
Thick=gram positive, treated with penicillin Thin=gram negative, treated with erythromycin |
|
|
Capsule
|
Layer of polysaccharides forming a gelatinous surface. Enables bacteria to escape macrophages like a slippery watermelon seed.
|
|
|
Strep. Pyogenes (as example for capsule)
|
Normally dormant in upper respiratory tract. If immune system is depressed, it will penetrate into body tissues and slip away from attacking macrophages.
|
|
|
Glycocalyx
|
Loose or fibrous capsule, slime layer enables attachment to smooth surfaces.
|
|
|
Strep. mutans (as example for glycocalyx)
|
Attach to teeth and absorb carbos in the mouth. Protects itself with hardened plaque. Gradually erodes enamel by releasing acidic wastes. Periodontal region may be invaded.
|
|
|
Endospores
|
Thick wall of peptidoglycan makes them most resistant living thing on Earth. Resist drying, boiling, freezing, alcohol, radiation, antibiotics.
Usually only a short stage in bacteria cycle. Reason why antibiotics are taken several days in a row. |
|
|
Toxins
|
Exotoxins: released by bacteria into surroundings
Endotoxins: part of bacteria cell wall, released when bacteria dies. Hinders blood clot formation and causes hemorrhaging. |
|
|
Clostridium botulinum
|
Exotoxin this bacteria produces is one of the most powerful toxins known.
Inhibits release of acetylocholine. In the disease botulism, flaccid paralysis occurs. |
|
|
Acetylcholine
|
released at junctions between nerves.
|
|
|
Clostridium tetani
|
Exotoxin released by this bacteria inhibits removal of acetylcholine at nerve junctions.
Causes muscular contractions, tetanus or lock jaw. |
|
|
C. Difficile (or C. Diff.)
|
Produces enterotoxin.
|
|
|
Enterotoxin
|
Exotoxin that targets GI tract. Protein enzymes cause diarrhea and rapid production of specific types of WBCs.
|
|
|
Flagella
|
Rigid strands of proteins bent like a helix.
|
|
|
Cholera bacteria (as example of flagella)
|
Swim using flagella through mucous coating of intestine.
|
|
|
Generation time
|
Interval of time between bacterial cell divisions
|
|
|
E. coli generation time
|
20 minutes.
One billion E. coli can form in one day. |
|
|
Pili
|
Appendages anchor bacteria and help transfer genetic material.
|
|
|
Anti-pili antibodies
|
Antibodies to block N. gonorrhoeae, which have become drug resistant.
|
