Microbiology Cocci arrangements & bacterial shapes
For differentiating and identifying unknown microbial species
Bergeys Manual of Determinative Bacteriology 1st series (phenotypic data) Gracillicutes Firmicutes Tenericutes Mendosicutes
For studying prokaryotic relationships and origins
Bergeys Manual of Systematic Bacteriology (rRNA sequencing data)
Which type of bacteria are more resistant to mechanical breakage (Gram-positive or -negative)? Why?
Gram-positive; because the cell walls of gram-negative cell walls contain only a small amount of peptidoglycan
Spheroplast
a Gram-negative cell that has undergone cell wall destruction by lysozyme
Protoplast
a Gram-positive cell that has undergone cell wall destruction by lysozyme
plasma membranes
a thin structure lying inside the cell wall, encloses the cell's cytoplasm
spirochete
another spiral cell containing periplasmic flagella (resembles a spring)
chemotaxis
bacteria move in response to chemical signal
sex pili
bacterial pili that are involved in the transfer of DNA from one cell to another
external structures
basal body, hook,filament
pleomorphism
caused by variations in cell wall structure (change in pH)
streptococci
cocci bacteria that form a chain pattern after dividing
sarcinae
cocci bacteria that form a cube of 8 after dividing
tetrads
cocci bacteria that form a group of 4 after dividing
What are the basic shapes of bacteria?
coccus, vibrio, rod, spirochete
Acid-fast bacteria (Mycobacterium sp. & Nocardia sp.)
contain mycolic acid (wax) must use acid-fast stain to ID TB & Leprosy
spirillum
corkscrew (helical) shaped spiral bacteria that are rigid
branching filaments
few bacteris produce multiple branches off of a basic rod structure
tumbles
flagellar rotation reverses causing cell to stop and change its course
vibrios
gently curved rod-shaped bacteria
What is the purpose of a prokaryote's capsule?
protect the bacteria from phagocytosis by host cells
prokaryotic cell size
range from 0.05-0.2
bacillus
rod-shape of bacteria
osmotic lysis
rupturing of a prokaryotic cell due to strong osmotic pressure outside the cell
runs
smooth linear movement toward a stimulus
coccus
spherical shape of bacteria
Gram positive cell (turns purple)
thick in peptiglycan techoic acid & lipotechoic acid one membrane
Gram negative cell (stains pink-red)
thin peptiglycan lipopolysaccharide 2 membranes porins
