General Microbio 01

monococcus

single, discrete cells, Neisseria

diplococcus

Neisseria meningitidis

micrococcus

pairs, tetrads or clusters, Micrococcus luteus

Lactococcus

chains, Lactococcus lactis

Streptococcus

Chains, Streptococcus agalactiae

Staphylococcus

grape-like cluster, Staphylococcus aureu

sarcina

cubical packet of eight cells, Sarcina ventriculi

creates

diplococci, streptococci

creates

tetrad

creates

staphylococci, sarcina

shape of bacilli

rod-shaped

Klebsiella pneumoniae

diplobacilli

Streptobacillus moniliformis

chains

Bacillus anthracis, Bacillus cereus, Bacillus subtilis

chains

Haemophilus influenzae

Coccobacill

shape of cocci

spherical

shape of spiral

comma, S/spiral shaped

Vibrio cholera

comma shaped, bent rod

Campylobacter jejuni

spirillum – rigid and spiral-shaped

Leptospira interrogans

spirochete – shape is flexible and changed during movement

what prevents cell wall growth at the site of their location?

Crescentin

How does Caulobacter crescentus attain its crescent shape?

asymmetric growth of cell wall

What wraps around the cell wall and run inside the cell body in the periplasmic space?

Endoflagella

What is the space between the outer membrane and the plasma membrane called?

periplasmic space

function of endoflagella

axial filament, external force on the cell wall

What causes the cell to deform into a flat-wave shape?

The stiffness of the helical endoflagella relative to that of the cell cylinder

What produces long filaments containing many rod-shaped cells and filaments branch out to form network?

mycelium

example of mycelium

actinomycetes

What forms a chain adjoining cells have a much closer spatial and physiological connection than streptobacilli?

trichome

example of trichome

cyanobacteria

pleomorphic

bacteria exhibiting different shapes

example of pleomorphic bacteria

Borrelia

What does Borrelia burgdorferi cause?

Lyme disease via blacklegged ticks

Bacterial cell envelope consists of

outer membrane, capsule, cell wall, cytoplasmic membrane

What is the first boundary isolating cytoplasm from external environment?

cytoplasmic membrane

cytoplasmic membrane consists of

phospholipids & membrane proteins

quality of protein in cytoplasmic membrane

Peripheral proteins are loosely connected to membrane and integral proteins are amphipathic

What is cytoplasmic membrane selectively permeable to?

sugar & proteins

What can pass frely through cytoplasmic membrane?

water & gas

Function of cytoplasmic membrane

Separating newly synthesized DNA from parental DNA, followed by cell division

What provides membrane fluidity?

Cholesterol

Function of cholesterol at high temperature

to increase the adhesion between phospholipids

Function of cholesterol at low temperature

to make rigid membrane fluid and allow small molecules to pass through

What does cyanobacteria produce that resembles steriod chemically?

hopanoids

What percentage of bacteria produce hopanoids?

4-5%

What condition increases hopanoid 10 times?

desication/cold

function of hopanoid

be similar to cholesterol, maintain cell membrane fluidity, increase van der waals forces between lipids to limit penetration of small molecules

What cannot synthesize steroid but incorporate it from the host?

Mycoplasma

what does unsaturated fatty acids do to maintain cell membrane fluidity?

increases fluidity

what does saturated fatty acids do to maintain cell membrane fluidity?

increases rigidity

what does branched chain fatty acids do to maintain cell membrane fluidity?

prevent tight packing and increase fluidity

what does cyclopropane fatty acids do to maintain cell membrane fluidity?

stabilize membranes under stress

Attributes of passive diffusion

concentration gradient, H2O, ethanol and gases (O2, N2 & CO2) freely diffuse

Attributes of facilitated diffusion

protein carrier, lipid bilayer stops big molecules, high—>low concentration, transport of glucose, amino acids, Na+, Cl-

Attributes of active transport

protein carrier, ATP used against concentration gradient

what is cell wall made of?

peptidoglycan/murein

What does peptidoglycan contain?

Two amino sugars: N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)
Peptide crosslink
Pentaglycine (only in gram positive bacteria)

What bonds with NAG & NAM to form a linear polymer in cell wall?

β-1,4-glycosidic

What is crosslinked by peptides in the cell wall?

Linear polymer of amino sugar

Difference between gram positive & gram negative bacteria

gram positive bacteria has peptidoglycan in cell wall and gram negative bacteria doesn’t

result of gram staining on gram positive & gram negative bacteria

gram positive - purple

gram negative - pink

Teichoic acid is present in which bacteria?

gram positive

How is teichoic acid charge?

negatively

What is teichoic acid comprised of?

linear, glycerol (or ribitol) phosphate repeating units

function of teichoic acid

maintains cell shape, regulates cell division, binds to host cell (ie. antigenic properties)

What are teichoic acid anchored to the cytoplasmic membrane called?

lipoteichoic acids (LTAs)

What are teichoic acid covalently bound to peptidoglycan called?

wall teichoic acids (WTA)

Where is the periplasmic space for gram negative bacteria?

between cytoplasmic membrane and outer membrane

Where is the periplasmic space for gram positive bacteria?

between cytoplasmic membrane and cell wall

function of periplasmic space

controls molecular traffic entering and leaving the cel

Function of periplasmic protein

transfers sugars, ions, amino acids, stores toxins

Which periplasmic proteins are enzymes for nutrient digestion?

phosphatase, protease

Which periplasmic protein is an enzyme for detoxification?

β-lactamase digesting penicillin

Which periplasmic protein is used for chemoreceptors?

Rcs System

What does the outer membrane contain?

lipopolysaccharide (LPS), lipoprotein and porin.

Which bacteria has outer membrane?

Escherichia coli, Pseudomonas
aeruginosa, Haemophilus influenzae,
Helicobacter pylori, Klebsiella
pneumoniae, Salmonella enterica.

What are the 3 parts of Lipopolysaccharide (LPS)?

O-antigen, core, lipid A

What is O-antigen?

A repetitive glycan polymer comprising 2-6 sugars

In which bacteria does the oss of the O antigen results in partial loss of virulence?

E. coli and Salmonella

What does LPS with O-antigen produce?

smooth colony

What does LPS without O-antigen produce?

rough colony (caused by mutation)

What is a site of immunologic specificity of o-antigen?

its antigenic to host

what do long o-antigens do?

restrict access of molecules to the bacterial surface

What tissues does o-antigen make bacteria adhere to?

epithelial tissue

What is core?

polysaccharide and exposed to
extracellular environment

What is core consist of?

heptose, 3-deoxy-D-manno-octulosonic acid/keto-deoxyoctulosonate, phosphate and ethanolamine

what is linked to keto-deoxyoctulosonate via ketosidic linkage?

lipid A

What is keto-deoxyoctulosonate an indicator of?

assays for LPS

what is lipid A?

A phosphoglycolipid and a membrane-anchoring region of LPS

what is lipid A consist of?

phosphorylated N-acetylglucosamine (NAG) dimer with 6 or 7 fatty acids (FA) attached

what is the most conserved structure in all gram-negative bacteria?

lipid A

What is LPS that contains lipid A called?

endotoxin

which bacterias contain endotoxin and are pathogens?

E. coli, Salmonella

What recognizes LPS?

TLR4

What does TLR4 do after recognizing LPS?

Triggers proinflammatory response (release cytokins) facilitating eradication of the invading bacteria