Chapter 4 Flashcards
Characteristics of Mycobacterium tuberculosis
- gram positive
- acid fast-
- rod shaped (bacillus)
Characteristics of Streptococcis pneumonia
- gram positive
- non-acid fast
- chains of cocci
a target of antimicrobials
PTG
binds to proteins involved in cell wall synthesis
- this prevents cross-linking of tetrapeptides and therefore WEAKEND glycan chain strength
penicillin
Penicillin is more effective against…
gram positive bacterium
- because of increased concentration of PTG
- penicillin derivatives produced to protect against gram negatives.
produced in many body fluids including tears and saliva
lysozymes
breaks bond linking NAG and NAM
-destroys structural integrity of cell wall
lysozymes
often used in laboratory to remove PTG layer from bacteria
lysozymes
some bacteria naturally lack cell wall…
Mycoplasma
cause mild pneumonia
-antimicrobials directed towards PTG are ineffective
bacterium of mycoplasma
account for strength of a membrane
sterols
have a wide variety of cell wall types
NONE contain PTG but some do have pseudopeptidoglycan
Domain Archaea
Delicate fluid structure
Surrounds cytoplasm of cell
Defines boundary
Serves as an essen’al semi-‐permeable barrier, between cytoplasm and the external environment
Cytoplasmic Membrane
What is the difference between PTG and pseudo-‐PTG
that NAM is replaced with N-‐acetyltalosaminuronic acid and the crosslink is a beta 1-‐3 glycosidic bond. hat is, a change in the glycan backbone.
some bacteria have protein appendages that are not essential to life, they aid in survival in certain environments
flagella
pilli
number and position used in clasification of flagella
polar
peritrichous
long protein structure
about 20 nm thick
responsible for motility
flagella
use propeller like movements to push bacteria
can rotate more than 10,000 revolutions per minute
flagella
some flagella are important in bacterial pathogenesis and example is
H. pylori penetration through mucous coat.
what is flagella driven by
proton motive force
flagella runs, are
(flagella rotations are responsible for runs and tumbles)
counterclockwize
flagella tumbles
clockwize
flagella are primarily found in what shaped bacteria
rod shaped (bacillus)
bacteria use flagella for
motility
flagella are motile through sensing chemicals called
chemotaxis
is chemical compound is nutrient
acts as attractant
if compound is toxic
acts as repellent
shorter and thinner than flagella
similar in structure
protein subunits
pili
pili that are used or attachment are called
fimbriae
function of pili
attachment
movement
conjugation (baterial sex)- machanism of DNA transfer, can be called the F-pilus
Accumulation of polymers
synthesized through excess nutrient
storage granules
example of storage granule
glycogen- excess glucose is stored in glycogen granules
small protein compartments that provide buoyancy to the cell
gas vesicles
these regulating vesicles allow organisms to reach ideal position in environment
gas vesicles
dormant cell types produced from sporolation
-can remain dormant up to 100 years
endospore
resistant to damaging conditions like heat and UV
endospore
vegetive cell produced through germination
endospore
common bacteria that produce endospore are
Clostridium and Bacillus
have no lipid bound organelles but still maintain variety of internal structures
bacterial cells
bacterial cell structures that are essetial for life
- chromosome
- ribosome
- blueprint for all essential portions and RNA
- MUST be replicated for essential cell division
- circular and double stranded
- resides in CYTOPLASM
- supercoiled structure
- chromosome
- typically, bacteria have a single chromosome
circular DNA molecule
- extra-chrmosomal
- encode characteristics
- independently replicates
- potentially enhances survival (antimicrobial resistance)
plasmids
involved in protein synthesis
composed of large and small subunits
names for 30S and 50S
30+50=70S (overlapping)
ribosome
S
stands for svedburg constant
roughly a measure of teritory in quanternary structure
where RNA gets busy and proteins are formed
ribosome
rRNA
16S
40S+60S=80S
-difference often used as target for antimicrobals
Eukaryotic ribosomal subunits
Eukaryotes have numerous organelles that set them apart from prokaryotic cells
- Nucleus= DNA
- MItochondria and Chloroplast=energy production
- Endoplasmic reticulum= protein and lipid synthesis
- golgi apparatus= trafficing and modification
- lysosome and peroxisome
defined as population of cells derived from a single cell
pure culture
- this is to study functions of specific species
pure culture obtained using special techniques
aseptic techniques
-minimizes potential contamination
to isolate pure culture cells are grown on liquid or solid forms of ..
media
pure culture liquid is called
broth media
used for growing large numbers of bacteria
broth media
broth media with addition of agar
solid media
marine algae extract
- liquifies at temperatures above 95 degrees C
- solidifies at 45 degrees C
- remains solid at room temperature and body temperature
Agar
bacteria grow in colonies on what surface
solid media surface
- all cells in colony descend from one cells
- 1 million cells produce 1 visible colony
method simplest and most commonly used in bacterial isolation
streak plate method
Laboratory is usually what kind of culture
batch culture
major factors that influence growth
- temperature
- oxygen
- pH
- water availability
- Optimum temperature -5 to 15 C
- found in Arctic and Antarctic regions
Psychrophile
- optimal temp 20 to 30C
- some can grow low to -5C
- important in food spoilage
Psychrotroph
25 to 45 C
- most common due to temperate environments
- disease causing
Mesophile
45 to 70C
-common in hot springs
Thermophiles
70 to 110C
- usually members of archea
- modified cytoplasmic membranes make them more rigid
- protein sequence that resist unfolding
Hypothermophiles
Absolute requirement for oxygen
-use 02 for energy production
Obligate aerobes
example of Obligate aerobes
e.g. Nocardia species
No multiplication in the presence of oxygen
-
Obligate anaerobes
ex/ clostridium
use fermentation in the absence of oxygen
– Facultative anaerobes
example of Facultative anaerobes
e.g. E. coli
e.g. Saccharomyces sp. Depending on carbon
source availability
Require oxygen in lower concentrations
-high oxygen can be bad for growth
Microaerophiles
example of Microaerophiles
Helicobacter pylori
indifferent to oxygen growth, with or without
Obligate Fermenter
example of Obligate Fermenter
Streptococcus pyogenes
Oxygen can bateriostatc but tolerated in
some anaerobes
– Aerotolerance in Anerobes
example of Aerotolerance in Anerobes
Desulfovibrio
