Eating Habits - third set Flashcards
molecular patterns are expressed on..
pathogens and nonpathogens
plasma membrane (gram -) where and what it’s made of
is thin structure lies inside the cell wall, encloses cytoplasm defines the external boundary of cell. made of phospholipids, proteins, and glycoproteins.
Plasma membrane has dynamic role
acts as selective barrier; monitors flow in both direction. ATP/energy demands constant, appropriate internal environment
membrane structure…
best explained by the Fluid Mosaic model. Membrane resembles a sea of lipids with an mosaic of embedded proteins and attached sugar molecules
Lipids (physio)
arranged as bilayer, composed mainly of phospholipids
proteins
are in motion laterally: grouped into 2 classes, Integral and Peripheral proteins
Cholera ToxR : Transmembrane protein ( Biosensor) (parasite swimming)
Allows for rapid sensing and activation of pathogenic functions ToxR
is able to detect acidity and high temps ( signs of host digestive system)
NH2 part reaches cytoplasm
- NH2 terminal domain binds to DNA sequence as a transcriptional activator in turn, activates cholera toxin gene expression as well as other virulence factors
transport system (small cars)
mechanism that facilitates small molecules to enter cell across the normally impermeable membrane
role of transport system
A. To bring in nutrients B. Expel waste products and substances harmful to the cell (efflux) C. Secretion
i. secretion of selective protein molecules which are structural components (like porins proteins of gram negative cells - made in cells) ii. toxins which are virulence factors iii. secretion of enzymes (ex. exoenzymes like amylase) - breaks down large substances for absorption
Transport process is..(PCCT)
PCCT
the functional outcome of activity of channel proteins / transport proteins / carrier protein / permeases
bacterial cell anatomy
AACE
cell envelope, appendages, cytoplasm, accessory structures
External structures
includes cell envelope and appendages
appendages
PEFF
flagella, fimbriae, pili and endoflagella
Flagella (spins..)
spins, forward, uses energy
2/3 energy used for flagella . long, semi rigid and filamentous appendage, aids in motility acts as a spinning motor, propels cell in forward direction flagella motility involves expenditure of cellular energy.
Flagella has 3 basic parts
Filament, hook and basal body
flagella arrangement - names (lamp)
monotrichous, peritrichous, amphitrichous, and lophotrichous
Monotrichous
single polar flagella, Ex: Pseudomonas aeroginosa
Peritrichous
flagella distributed over entire surface, Ex: E. coli
Amphitrichous (spiral voltans)
tuft of flagella at each end of cell Ex: Spirillum volutans
Lophotrichous
two or more flagella at one pole of cell, Ex: Helicobacter pylorii, helps bacteria to cross the mucosal coating of the intestinal epithelium
Favorable stimulus
positive taxis
Unfavorable stimulus (NY)
negative taxis
Attractant and Repellent (runner)
Attractant: more runs of longer duration and less tumbles Repellent: more tumbles
Pili (pill)
F pili - shorter than flagella, 1- 10 per cell, always evolves
Pili (sing pilus) - also called sex pili or F pili or conjugation pili; shorter than flagella - usually 1- 10 sex pili per cells - aids in joining cells of opposite mating types during conjugation process - is one of the methods of genetic exchange of genetic material between bacterial cells. no sexual reproduction. always evolves due to exchange of genetic material
Fimbriae: (variation of pili) (black bug crawling up pole)
- fimbriae number varies (few to thousands); distributed throughout or have polar concentration- aids in attachment to substrate (ex. epithelial surface) as well as to one another - harbors adhesin (special molecule), either at the tip or all along it’s length
Both pili and fimbriae have pilin proteins. pilin proteins acts as PAMP.
Endoflagella
it is an appendage - present in Spirochetes, Ex: treponema paladium and borrelia berdoffori there is an outer sheath (membrane), below which are fibrils (axial filaments) sheath is anchored at one end and spirals around cells - uses cork screw motion to drill into viscous tissues of their host
chromosomes (strand)
- it’s single, circular, double stranded DNA molecule (supercoiled) with associated
proteins - are nonhistone proteins; exception vibrio cholera - anchored to plasma membrane; confined in nucleoid area
plasmids
- small, extrachromosomal DNA molecules- self replicating units - when a cell divides, plasmid DNA replicates and is distributed to daughter cells. are not required for metabolism / survival under normal condition. presence provides selective advantage to the bacteria like antibiotic resistance.
plasmid functions
plasmid carry genes for activities such as,- antibiotic resistance - toxins production -plasmid DNA may code for toxin
plasmid types
BRVF
fertility, resistance, virulent, Bacteriocin plasmid
Fertility plasmid
codes for the sex pili ( F pili) - involved in conjugation process
resistance plasmid
carry resistance genes for antimicrobial agents (antibiotics and heavy metals) heavy metals stop bacterial growth - as resistance genes - are self transmissible plasmids - aka plasmid DNA codes for sex pili
Bacteriocin plasmid
carry genes for the bacteriocin. bacteriocin toxin kills other competing bacteria cells that lacks bacteriocin plasmid, carried by intestinal bacterias.
virulent plasmid
carry genetic information for virulence structures, enzymes or toxins. - 3 components of toxin - all 3 needed for efficacy
plasmid - self transmissibility (3 types)
has genes that codes for sex pili, origin of transfer, and mobilization of the genes.
copy number
number of copies of each kind of plasmid per cell
host range
ability of plasmid to multiply in cell type
ribosomes (aka ribonucleoprotein particles) (translator w/ target)
associated with bacterial translation (means protein synthesis) - are smaller, less dense than eukaryotic ribosomes (70 S vs 80S) made of 2 subunits; preferred target site of some antibiotics action. many antibiotics target small units, can tell between our subunits. some target large, erythromycin. subunit is made of RNA and proteins
Metachromatic granules (aka volutin granules) (plants)
PPANE
when bacteria are growing in phosphorus rich environment. meta means change, choromatic means color- represents polyphosphate granules- can be degraded and used as iP (inorganic phosphorus) source for ATP synthesis, nucleic acid, enzyme reaction, phosphoproteins, phospholipids- stains red with some blue dyes (methylene blue- characteristic feature of Corynebacterium diptheriae
Polysaccharides granules
includes starch and glycogen - they are storage depot for carbon and energy source- clinically useful for Chlamydia sps identification
Lipid inclusion (poly β- hydroxy butyric acid) (poly)
represented by inclusions of poly β- hydroxy butyric acid; surrounded by monolayer membrane - (hydrophobic lipid)- like polysaccharide, they are carbon and energy storage polymer- observed in Mycobacterium sps - used for mycolic acid synthesis
integral proteins
extend into or through the lipid bilayer - typically are trans membrane proteins / permeases. (channel or transport protein) ex. cholera membrane trans protein acts as a biosensor.
Peripheral proteins
attached to inner or outer surface of membrane- functions as enzymes, scaffold, receptors etc. Scaffold helps maintain structure
filament (part of flagellum)
long “whip like” structure of constant diameter. no covering structural component. flagallin - acts as a PAMP- TLR recognizes flagelin. Ecoli 0157:H7 - this is the hook protein
hook
wider part to which filament is attached, made of different protein, not flagellin
basal body
(at the end of the flagella) anchors flagellum to the cell wall and membrane
- includes a central rod inserted into a series of rings in Gram negative.
Rotation is either clockwise or anticlockwise along its axis. Gram positive only 1 pair of rings attached to membrane Gram negative 2 pairs of rings - an outer and inner one (outer - cell wall. Inner - attached to cytoplasm - gram negative) no whiplashing side to side
surface of bacteria always has…(negative ta)
a net negative charge on bacterial cell surface because of phosphate. bacteriophages (viruses that attack bacteria) exploit techtoic sites for attachment
- all endotoxins….(symptoms HFND)
HFND
produce the same signs and symptoms, though to different degree (irrespective of the microbe symptoms include fever, diarrhea, DIC a (Disseminated intravascular coagulation) causes tissue necrosis (cuts off nutrient and oxygen supply) hemorrhage
endotoxins have the same mode…(clotting action)
of action, irrespective of the species. all clotting factors are used up, leads to hemorraging
Narrow host range (same)
F plasmid in one cell type - only transferred between similar cell types - gram + to gram +
Wide host range (Rampant)
R plasmid - resistance plasmid - multiplies in difference species of bacteria - staph, bacillus, etc. antibiotic resistance due to R plasmid- they can jump species barrier - can jump between E.coli and yeast
no antibiotics are designed to target…
lipopolysaccharide or outer membrane (endotoxin)
cause of collapse in DIC (dying clots)
(disseminated intravascular coagulation) caused when Lipid A clotting is activated, clots block smaller blood vessels. DIC leads to tissue necrosis. some of smaller blood vessels get blocked
Spheroplast
gram - cells partially stripped of its cell wall. can’t completely strip gram - cell wall - always some part still there. aspect of antibiotic resistance.
gram negative bacteria ex.
E. Coli and enterobacteria
compliment activation (the Cs - wake up)
part of your defense system. complement get activated, 9 of them - C1 - C9 are compliment protein in our body. once activated, they form MAC complex. Punches holes in invading cell. content leaks and cell dies .and MAC lysis (innate immune response). Mac = membrane attack complex.
Self transmissibility plasmid has genes..
that codes for sex pili origin of transfer as well as mobilization
membrane helps maintain..
constant internal environment because ATP sythensis demands constant internal evironment
static structure
anything can go in and out
electron transport chain occurs where
periplasmic space cytoplasmic space
innate defense system (count)
1st, 2nd and 3rd lines of defense
1st line of defense (PCM)
physical barrier, chemical barrier, normal microflora
chemical barrier (stomach and eyes)
acidic ph of stomach, lysozomes
2nd line of defense (light sab)
compliment proteins and MAC lysis, inflammation, phagocytosis
3rd line of defense
B/T cells (adaptive defense sytem)
Neisseria gonorrhea and pathogenesis….
gonorrhea can be pathogenic and nonpathogenic. Pathogenic has wild type fibria with adhesin, therefore able to colonize urinary tract epithelial cell membrane. Non pathogenic form is a mutant form, this one fails to colonize, and is flushed out by urine.
e.coli attachment of bacterial cell can be..(poly)
nonspecific -due to sticky capsular polysaccharide. specific attachment is due to fimbraiae adhesins (which it recognizes some specific sugar on host membrane - glactose or mannose
specific attachment due to fimbraiae adhesins…(gs)
it recognizes some specific sugar on host membrane glycolipids or gycloproteins
The capsule and fimbriae are
virulent factors
cranberry juice and UTI
have organic components, tannins, that interferes with with adhesion of sugar molecules. 1. it has to be unprocessed. 2. organic compounds of cranberry juice are filtered as such. there is no metabolism or detoxification. 3. these organic compounds can withstand the chemical composition of urine. not altered or broken down.
Bordetella sps adhesin (whooping cough)
have 2 different types of adhesins on cell.
chemotaxis
most important - Chemotaxis is the movement of an organism in response to a chemical stimulus. bacteria moving towards attractant, nutrients, becomes positive taxis. Repellants - toxic, heat. cells moves away from it, negative taxi.
runs
a sustained unidirectional movement, uninterrupted. more toward attractants
tumbles
sudden stop or cessation, cell rolls over several times, resumes run in a different direction. tends to move away from stimulus towards attractant
taxis (hail)
sensing and responding to stimuli
no role in transport or permeability
outer membrane lipopolysaccharide
Teichoic acid - recognized by the toll-like receptors, and…
once engaged, the cells secrete
pro-inflammatory cytokines. that initiates inflammation process and eventually eliminates the pathogen.
TNF alpha, IL-1, 6 ,18 etc
secreted from defense cells. is a cell signaling protein involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction. (pro-inflammatory cytokines) promotes inflammation process for eliminating pathogen
plasmid transmissibility can be either…
self transmissible or non self transmissible.
plasmid copy number is..
low and high
plasmid host range is…
narrow and wide. Wide some referred
to as promiscuous, they can jump species barrier -can jump between E.coli and yeast
transmissibility
ability to be transferred / exchanged between cells via conjugation
low copy plasmid
F plasmid, 1-2 copies per cell - below 10 is low copy
high copy plasmid
10 - > 500 copies per cell
r genes
Inside R plasmid - resistance genes - codes for resistance characteristics
rtf - resistance transfer factor
codes for plasmid transfer to other cells via conjugation
bacterial ribosomes
small subunit - 30S, large subunit 50 S
eukaryotic ribosomes
40S small subunit, 60S large subunit
Inclusion Bodies (1 = 1)
storage granules or non-functional units, in cytoplasm. 1 bacterial cell - 1 type of inclusion (usually)
bacterial cell anatomy (AACE)
envelope, appendages, cytoplasm and accessory structures
External structures
includes cell envelope and appendages
the appendages are
flagella, fimbriae, pili and endoflagella
inclusions are..(volcano)
volutine granules, polysaccharide granules and B-hydroxy butyric acid
where is membrane attack complex (MAC) formed
typically on the surface of pathogen cell membranes as a result of the activation of the host’s complement system
Non self transmissible plasma membrane needs help from…
F plasmid or a self transmissible plasmid. plasmid doesn’t have gene for sex pili, but have genes for origin of transfer as well as mobilization genes.
cell envelope includes..(envelope)
capsule, cell wall, cytoplasmic cell membrane
accessory structures include..(crip)
chromosome, plasmids, ribosomes, inclusions
anti-imflammatory drugs used when
TLRs are activated bc they cause inflammation
endotoxin fever induction
bacteria recognized as non self, macrophage active, pick up bacteria,. oxygen will flush and bacteria will die and lipid A will be released. macrophage will be “activated” and it will secret interlukin 1 (which is pro-inflammatory) into bloodstream, travel to hypothalamus. activates an enzyme called cox enzyme, or cyclo oxygenic. will generate prostoglandins. it resets the switch for temperature regulation
syphilis
deliberately injected with malaria, to induce fever. mild fever, ok
advantages of fever
you take rest , and energy is used to fight bacteria. increased temperature may slow bacterial growth.
Increased temperature also enhances cellular reactions of the defense cells in eliminating pathogens (as we heat in chemistry to increase chemical reaction rates
svedberg units
70K revolutions per minute for bacteria. for humans it’s 80k revolutions for minute.
capsule and fimbrae are both
virulent factors
membrane sheath absent in..
flagella
e.coli plasmid can acquire..
e.coli normally present does good for our body, same one can acquire plasmid from other transient bacteria w/in intestine and cause diarrhea.
no cholesterol in membrane except
mycoplasma - smallest living, walking pneumonia
protoplast
gram + stripped of cell wall
ex of virulent plasmids
ex. - Bacillus anthracis and toxin - carry 2 virulent plasmids per cell. Plasmid usually in DNA, but in anthrax it’s in the plasmid capsule, this is an exception. I1st codes for polypeptide capsule - poly d. glutamic acid. 2nd plasmid - codes for anthrax toxin
metabolism is the sum of
all chemical reactions inside the cells
