Bacteria Morphology Flashcards
What are some of the most often looked at characteristics with a microscope
-Shape and arrangement
*many scientific names are based on the more common shapes and arrangements
Three general groups of bacterial shapes
- spiral
- coccus (sphere)
- bacillus (rods)
arrangement
how the bacteria species orients itself relative to one another
diplococci
a pair of spheres
Arrangement: two spheres remain attached after division
streptococci
long chain of spheres
arrangement: long chain of spheres that remain attach after division
Tetrads
cluster of four spheres
Arrangement: a sphere divides in two planes and remains attached
Sarcinae
cuboidal packets of eight
Arrangement: a sphere divides in four planes and remains attached
staphylococci
grape like bunches of spheres
Arrangement: divide at random places
spirillium (Type of spiral)
short, stiff and loosely round
spirochete (Type of spiral)
long, flexible, and tightly wound
vibrio (Type of spiral)
curved rods (comma like)
coccobacillus
an intermediate stage between coccus and bacillus
-bacilli all divide into one plane
pleomorphic
bacteria that vary in shape and size
Star
-type of bacteria that is star shaped
Random Bacillus
single, unpaired rods
Diplobacilli
pair of rods
streptobacilli
chain of rods
Palisade
rods remain attach by snapping division
-separate division of endospore forming
Reproduction
-all bacteria produce asexually by binary fission (most common)
Binary Fission
- Cell replicates its genome and attaches it to the cell membrane
- Cell membrane elongates, separates genome
- Cell membrane forms between genome copies
- Daughter cells separate
Why do prokaryotes have unique arrangements ?
-arrangements are a result of two aspects of cell division during binary fission
1. The plane at which the cell divides
2. Separation of daughter cells
Vibrio Cholerae
Gram reaction: Negative
Shape and Arrangement: vibrio (singles)
Found: associated with contaminated seafood and water supply
Disease: cholerae (diarrhea)
*difficult to see shape/size due to its small size
Escherichia coli
Gram reaction: negative
Shape and Arrangement: bacillus (single)
Found: associated with fecal contaminant food and water
Disease: strain 0157-H7 can cause renal failure, symptom is diarrhea
Borrelia Burgdorferi
Gram reaction: negative
Shape and Arrangement: spirochete
Found: Small animals are the host for the disease (tick –> humans)
Diseases: Lyme Disease
Helicobacter pylori
Gram reaction: negative
Shape and Arrangement: spirillum (singles)
Found: mucus lining of human inner stomach
Diseases: gastric ulcers
streptococcus pyogenes
Gram reaction: positive
Shape and Arrangement: streptococcus
Found: Human skin and in throat
Diseases: pharyngitis, cellulitis, impetigo
Bacillus anthracis
Gram reaction: positive
Shape and Arrangement: streptobacillus
Found: in soil
Diseases: anthrax (skin and lung infection)
staphylococcus (epidermis and aureus)
Gram reaction: positive
Shape and arrangement: staphylococcus
Found: S. epidermis and S. aureus are normal microbiota of the skin.
Diseases: S. aureus can cause skin, lung, heart valve, and bone infections ( Osteomyelitis)
S. Epidermis can cause wound infections, boils, sinus infections
Neisseria gonorrhoeae
Gram: negative
Shape: diplococcus (coffee bean)
Found: lives in human urogenital track
Disease: gonorrhea
