•Appendages may provide motility
•Flagella
•Axial filaments
•Appendages allow for attachment to surfaces
•Fimbriae
Gram Negative vs Gram Positive Cells
Neg- has outer membrane, thin peptidoglycan
Cell Membrane
•Composed of phospholipids and proteins
•Responsible for selective permeability
-Thick peptidoglycan layer
-Outer membrane
-Cell membrane determines shape of bacteria
(gram neg or positive)
pos
-Cell wall prevents entry of small molecules
-Cell membrane composed of phospholipids and proteins
-Generally harder to kill with antibiotics
-Less permeable to small molecules
(gram neg or positive)
fill in
Within the Cell Cytoplasmic matrix, Nucleoid, Cytoskeleton
•Cytoplasmic matrix provides water for biochemical reactions
•Nucleoid contains genetic material
•Cytoskeleton provides support
Ribosomes
•Responsible for protein synthesis
•Prokaryotic ribosomes 30S + 50S = 70S
Inclusions
•Contain stores of nutrients
Endospores
•Survival structures formed by bacteria in the genera Bacillus and Clostridium
• in response to poor growth conditions
•Resistant to heat, cold, chemicals, radiation…
-special staining technique
What is true about endospores?
a)Found in Bacillus and Clostridium
b)May survive 1000’s of years
a)Aid in attachment to body surfaces(false)
d)Protect the cell against dehydration(false)
e)Produced in response to heat, cold, or radiation(false)
•95% of bacteria are found in one of three shapes
cocci, bacilli(rod), spirals(spirillum & spirochetes)
Bacterial Arrangement
•Dependent on division of individual cells. Cocci have more arrangements than rods
•Division along multiple planes produce more complex arrangements (random cuts)
Rods divide only along
•transverse plain (width of the cell)
•May produce streptobacillus
•Some species (Corynebacterium) sometimes produce palisades arrangement with cells parallel to one another or snapping into a “V” shape
A coccus that divides on random planes of division (front to back, top to bottom, left to right…) will likely produce
a)Staphylococcus
Bacterial Size Coccus, Bacillus, Spirillum
•Coccus 1-2 μM
•Bacillus 2-20 μM
•Spirillum10-200 μM
classification
Domain
kingdom
phylum
class
order
family
genus
species
•Bergey’s manual of Systematic Bacteriology & Medical Microbiology System
•Bergey’s manual of Systematic Bacteriology
•Everything you ever wanted to know (and a lot you didn’t)
Medical Microbiology System (Not really a system)
•Deals only with agents of human disease
•Classifies bacteria phenotypically, using common laboratory tests
•Much easier to use….