Lesson 8 Flashcards
• procaryotic,unicellularorganisms
• usuallydivide by binary fission
• Cell wall contains peptidoglycan
or mucopeptide
Bacteria
three general shapes of bacteria:
1.coccus or berry
2.bacillus or rod
3.spirillum or spiral
When the rod is short and plump, it is
called _____&&?
coccobacillus
Bacillus or rod when it is gently curved?
vibrio
Bacteria that is spiral shaped?
spirillum or spiral
length( 0.5 to 1 μm) in diameter and may pointed at
the end
Coccus/Cocci
Cocci by pair
(Diplococcus)
Cocci in chain
(Streptococcus)
In cubical packets of eight
(Sarcinae)
Cocci in irregular clusters
(Staphylococcus)
Example of (Diplococcus) bacteria ?
Neisseria gonorrheae
and D. salivarious
Example of (streptococcus) bacteria?
S. pneumoniae
Example of (Sarcinae) Bacteria?
S. ventriculi
Example of (Staphylococcus) bacteria?
S.
aureus
Rod shape: Bacillus occur as slender rod?
Salmonella
typhi (typhoid fever)
Rod shape: Bacillus that is rectangle with square ends as
anthrax
Bacillus anthracis
Rod shape: Bacillus that is some are curved ?
Vibrio cholerae
Shape of Bacteria that are Twisted rod that resemble a
cork screw
Spiral shape
Examples of spiral shapes bacteria
Spirochetes Treponema
pallidum (cause of syphilis)
and
• Leptospira (leptospirosis)
(only one species
but with variable shape)
Pleomorphic
rod shaped
but in culture they display
variations such as club-
shaped, swollen, curved,
filamentous and coccoid
Corynebacterium
diphtheriae
Actino means ?
ray
mykes means
fungi
(Mold like or filamentous bacteria
• Have elongated cells which have definite tendency to
branch to produce branched mycelium and multiply by
spores
• The cell structure, is procaryotic like the proper bacteria
Actinomycetes
–cause potato scab
Streptomyces scabies
cause
nocardiosis, an infection of the skin,
lungs and brain of humans
Nocardia asteroides
Beneficial actinomycetes that are source
of streptomycin antibiotic?
Streptomyces griseus
Beneficial
Actinomycetes that is source of tetracycline
antibiotic
Streptomyces aureofaciens
Beneficial
Actinomycetes that is source
of Nystatin- an antifungal
agent.
Streptomyces norsei
External Structures of the True
Bacteria that sprout from
surface of bacteria; not present in all species;
Appendages
Parts of true bacteria that provides motility?
(flagella and axial
filaments)
Parts of true bacteria that provides attachments or channels?
(fimbriae and pili)
Parts of appendages that confers motility or self-propulsion.
Flagella/Flagellum
Tyre or false .
Generally all spirilla, about half of the bacilli and a small
number of cocci are not flagellated.
False
Generally all spirilla, about half of the bacilli and a small
number of cocci are flagellated
flagella attached at one
or both ends of the cell?
polar arrangement
Bacteria with a single flagellum
monotrichous
Bacteria with small bunches or tufts of flagella
emerging from the same site e.g. Vibrio fischeri
lophotrichous
Bacteria with flagella at both poles of
the cell
amphitrichous
flagella
dispersed over surface of the cell
e.g. Escherichia coli
Peritrichous arrangement
no flagella
Atrichous
• a type of internal flagellum
• enclosed between the cell
wall and cell membrane;
• curlclosely around the
bacterium
• give spirochetes wriggly
mode of locomotion
Periplasmic flagella or
axial filaments
small, bristle-like fibers sprouting from
surface of many bacterial cells
• have tendency to stick to each other and to surfaces
• enable the bacteria to bind to specific receptor structures and
thereby to colonize specific surfaces.
fimbriae/fimbria
Appendages for Attachment
and Mating
fimbriae/fimbria
Pilus (sex pilus)
The Surface Coating
• Elongate, rigid, tubular structure made up of protein called pilin
• Found only in Gram-negative bacteria
• Involved in the partial transfer of DNA from one cell to another
during conjugation
Pilus (sex pilus)
also known as glycocalyx
• made up of repeating polysaccharide units, protein or
both
• protects the cell or may cause it to adhere to its
environment
• differ among bacteria in thickness, organization
and chemical composition
The Surface Coating
Two forms of glycocalyx
slime layer
capsule
thin, loose soluble sheath
- protects bacteria from loss of water and
nutrients
- for adherence to surface
Slime layer
What type of streptococcus that forms Whyte dental plaque on teeth due to surface slime?
Streptococcus mutans
Bound more tightly to the cell than a slime layer encapsulated bacterial cells are more virulent because it protect the bacteria from phagocytes.
Capsules
Bacteria have thick capsules which makes it tightly resistant to drugs.
Mycobacterium tuberculosis
gives shape to the bacterium
• provides structural support that keeps bacterium from bursting or collapsing
because of changes in osmotic pressure.
• made up of peptidoglycan (PG) which in turn is made up of (alternating glycans,
N-acetyl glucosamine (G) and N-acetyl muramic acid(M) bound together in long
strands
Cell wall
Cell wall is made up of peptidoglycan (PG) which in turn is made up of (alternating glycans, what is the alternating glycans?
N-acetyl glucosamine (G) and N-acetyl muramic acid(M)
an enzyme that
degrades the peptidoglycan layer, or penicillin, an antibiotic that
prevent cell wall synthesis.
lysozyme
Gram positive + lysozyme =
protoplast (cell wall completely removed)
Gram negative + lysozyme =
spheroplast – only a part of cell wall is
removed
What are bacteria that naturally lack cell
wall or cell wall-deficient bacteria;
Mycoplasma
Phytoplasma
Spiroplasma
Bacteria that causes primary atypical pneumonia in humans.
Mycoplasma pneumoniae
Bacteria that is (known as mycoplasma-like organisms
before) plants – that cause coconut lethal yellowing, little
leaf
Phytoplasma
Bacteria that cause corn stunt and citrus decline
Spiroplasma
• thin (5-10 nm) flexible sheet molded completely around the
cytoplasm
• composed of lipid bilayer with embedded protein
• regulate transport of substances into and out of the cell
• site for energy reactions, nutrient processing and
synthesis
The cell Membrane
• found encased by the cell membrane
• gelatinous solution made up of water (70 – 80%), and a
complex mixture of nutrients including sugars, amino acids
and salts
• site for many biochemical and synthetic activities of the cell
The Cytoplasm
Cytoplasm contains ?
Chromatin body
Plasmids
Ribosomes
Cell inclusion
represents the
genetic material of bacteria which come
as single circular strand of DNA; found in
cell area called nucleoid
Chromatin body
essential pieces of DNA
duplicated and passed on to offspring;
confer protective traits such as
resisting drugs and producing toxins
and enzymes
Plasmids
site of protein synthesis
Ribosomes
• represent stored food like glycogen; in some aquatic
bacteria,
• they come as gas vesicles for buoyancy and flotation.
• Some contain crystals of inorganic compounds, termed
metachromatic granules
Cell inclusion
• Dormant bodies produced by Bacillus, Clostridium and Sporosarcina
for withstanding adverse conditions and facilitating survival
• The depletion of nutrients, like adequate carbon or nitrogen source,
stimulates vegetative cell to begin endospore formation(6-8 hrs)
The bacterial endospores
What are the bacterial pathogens are endospores former?
Bacillus anthracis
Clostridium tetani
C. perfringens
C. botulin
Bacterial pathogens that cause anthrax?
Bacillus anthracis
A coating or layer of molecules external to the cell wall. It serves protective, adhesive, and receptor functions. It may fit tightly or be very loose and diffuse.
Glycocalyx
Composed of condensed DNA molecules. DNA directs all genetics and heredity of the cell and codes for all proteins.
Bacterial chromosome or nucleoid
Double-stranded DNA circle containing extra genes.
Plasmid
An elongated, hollow appendage used in transfer of DNA to other cells.
Pilus
Tiny particles composed of protein and RNA that are the sites of protein synthesis.
Ribosomes
Long fibers of proteins that encircle the cell just inside the cell membrane and contribute to the shape of the cell.
Actin cytoskeleton
Specialized appendages attached to the cell by a basal body that holds a long, rotating filament. The movement pushes the cell forward and provides motility.
Flagellum
Fine, hair-like bristles extending from the cell surface that help in adhesion to other cells and surfaces.
Fimbriae
Stored nutrients such as fat, phosphate, or glycogen deposited in dense crystals or particles that can be tapped into when needed.
Inclusion/Granules
A semirigid casing that provides structural support and shape for the cell.
Cell wall
A thin sheet of lipid and protein that surrounds the cytoplasm and controls the flow of materials into and out of the cell pool.
Cell (cytoplasmic) membrane
Extra membrane similar to cell membrane but also containing lipopoly saccharide. Controls flow of materials and portions of it are toxic to mammals when released.
Outer membrane
Dormant body formed within some bacteria that allows for their survival in adverse conditions.
Endospores
Dormant body formed within some bacteria that allows for their survival in adverse conditions.
Endospores
Water-based solution filling the entire cell.
Cytoplasm
prokaryotic single-celled organisms belonging to
Domain Archaea
Archaea
Archaea also known as ____?
Extremophiles
Example of harsh environments where Achaea can sustain?
oceans, hot springs, marshlands, and gut of humans
Archaea can sexually reproduce through _____&
binary fission,
fragmentation, or budding
The reason why archaea belongs to the domain Eukarya rather than to bacteria
Archaea and eukaryotes share a number of
ribosomal RNA sequences that are not found in
bacteria
Archaea contains __________ instead of peptidoglycan in their cell wall.
pseudo-peptidoglycan (pseudomurein)
•strict anaerobes (live
without O2); convert CO2
and H2
into methane gas
(CH4
)
•important in biodegradation
of organic matter and most if
not all natural gas on Earth
has accumulated from their
metabolism
the methanogens (e.g.
Methanobacterium)
True or false.
Methanobacterium are motile
False. Methanobacterium are nonmotile
“salt-loving” or “ocean bacterium
• require oxygen and very large
amounts of salt (NaCl) for
metabolism and reproduction
The halophiles ( e.g.
Halobacterium)
Shape and color of Halobacterium?
Either Rods or cocci, either red or purple
Metabolism of Halobacterium?
aerobic metabolism
Temperature of the environment that Halobacterium grows best?
42 degree Celsius
high temperature loving
• flourish at temperatures between 80oC and 113oand
cannot grow at 50oC
hyperthermophiles
Example of hyperthermophiles?
Thermoplasma acidophilum and Thermophilus
• organisms are those that thrive under highly
acidic conditions (usually at pH 2.0 or below).
(Acidophiles) acidophilic organisms
These organisms can be found members of
Archaea, Bacteria and Eukarya
Acidophiles
produced by extremophiles are useful in
industrial production procedures and research
applications because of their ability to remain active
under the severe conditions
Extremozymes
Taq polymerase enzyme used in polymerase
chain reaction (PCR – a method of in vitro DNA
replication) is from what bacterium?
Thermos aquaticus
A methane gas from Methanogens
Biofuel
It may prove to be valuable bioremediation
agents for the treatment of saline effluents and
hypersaline waters contaminated with toxic compounds
that are resistant to degradation.
Halophiles
One example there examoles is the metals such as gold, silver, copper, zinc,
nickel, and uranium. The organisms used in this process
are acidophiles.
Biomining
Bacteria are producers of a host of
antibiotics, antifungals, and antitumor molecules. True or false
False. Extremophiles
