Micro Physio Flashcards by Jolyca Nechole Orong

basis of phylogenetic tree of life

comparative analysis of small subunit ribosomal RNA gene sequences showing evolutionary relationships

How well did you know this?

Not at all

Perfectly

3 relevant features of prokaryotes

nuclear membranes are absent, which allows couple transcription and translation
smaller than eukaryotic
cytoplasmic membrane is multifunctional in prokaryotes and represents the defining structure of the cell

How well did you know this?

Not at all

Perfectly

5 superpyhla of archaea

nanoarchaeota, euryarchaeota, thaumarchaeota. crenarchaeota, korarchaeota

How well did you know this?

Not at all

Perfectly

contains most cultured species of archaea, metabolically diverse and includes methanogens, halophiles, thermophiles and hyperthermo

euryarchaeota

How well did you know this?

Not at all

Perfectly

contains nitrifying archaea; many members are uncultured, characterized by the use of 16s rrna genes

thaumarchaeota and cryptic archaeal phyla

How well did you know this?

Not at all

Perfectly

represented by a single species; cannot grow in pure culture and only replicate when attached to the surface of their host organism (1)

nanorchaeota (DPANN), species- Nanoarchaeum equitans (one of the smalles cellular organism with smallest genome among species of archaea)

(1)Ignicoccus hospitalis- a hyperthermophilic species of crenarchaeota whose name means ‘the hospitable fireball’

nano attached to igni

How well did you know this?

Not at all

Perfectly

many cultured isolates which are thermo/hyper using sulfur compounds as either electron donors or acceptor

crenarchaeota

How well did you know this?

Not at all

Perfectly

t/f some archaea are natural flora in the human body

true

How well did you know this?

Not at all

Perfectly

t/f there are archaea that cause diseases

f, no conclusive evidence

How well did you know this?

Not at all

Perfectly

what domain is similar to archaea in terms of transcription machinery specifically in promoter recognition and initiation of transcription;

eukarya

How well did you know this?

Not at all

Perfectly

only has one characterized species; recovered from obsidian pool a hot spring in yellowstone national park; species yet to be grown in pure culture

korarchaeota; Korarachaeum cryptofilum ‘ the secret filament of youth’

How well did you know this?

Not at all

Perfectly

major composition difference in cell wall of bacteria vs archaea

presence of NAG and NAM in bacteria with beta 1-4 glycosidic linkage
while NAG and NAT in archaea with beta 1-3 glycosidic linkage

How well did you know this?

Not at all

Perfectly

major composition difference in cell membrane of bacteria vs archaea

B= phospholipid bilayer, esther linked unbranched fatty acid to glycerol
A= branched isoprene chains, lipid monolayer in some archaea

How well did you know this?

Not at all

Perfectly

the subunit composition and architecture of archaeal RNA polymerase is strikingly similar to

eukaryotic RNAPII

How well did you know this?

Not at all

Perfectly

examples of DNA transfers in archaea

transformation in euryarchaeota
vesicle transport in thermococcales
transduction in archaea
conjugation in sulfolobaceae
cell fusion in haloarchaea
chromosomal DNA exchange in crenarchaeota

How well did you know this?

Not at all

Perfectly

polymers of repeating units of glycerol or ribitol joined by phospohates; amino acids (D-ala) or sugars (glu) ar attached to gly/rib; covalently linked to murein through muramic acid; connected/ embedded in PG layer to membrane lipids

teichoic acids

How well did you know this?

Not at all

Perfectly

linear polymers of 16-40 phosphodiester-linked glycerophosphate residues covalently linked to the cell membrane

lipoteichoic acid

How well did you know this?

Not at all

Perfectly

properties and importance of teichoic acid

highly antigenic
anchors the wall to cell membrane
provides high density of regularly oriented charges
storage of phosphorus
facilitates attachment of bacteriophage
inhibits the activity of autolytic enzymes which hydrolyze the murein

How well did you know this?

Not at all

Perfectly

cell wall substances: acidic polysaccharides containing uronic acids

teichuronic acids

How well did you know this?

Not at all

Perfectly

cell wall substances: important in classification of some gram +

neutral polysaccharides

How well did you know this?

Not at all

Perfectly

cell wall substances: may substitute for whatever function of LTA

other glycolipids

How well did you know this?

Not at all

Perfectly

waxy lipids found in mycobacterium

mycolic acids

How well did you know this?

Not at all

Perfectly

unique in the gram neg cell wall

LPS

How well did you know this?

Not at all

Perfectly

gneg lps; embedded in the membrane as part of the lipid bilayer; hydrophobic; composed of 2 glucosamine residues linked B-1,6 backbone with 4 identical fatty acids

lipid A

How well did you know this?

Not at all

Perfectly

gneg lps; shows high to moderate variability consists of hexoses

outer core

gneg lps; shows low structural variability; consists of 2-keto-3- deoxyoctonate (KDO), heptose, ethanolamine, and galactose

inner core

gneg lps; short polysach extending outward from the core; consist of peculiar sugars which varies between bacterial strains; not essential for variability

LPS o antigen

gneg lps importance

avoidance of host defenses (o antigen) contributes to the neg charge on the cell's surface stabilizes membrane structure acts as endotoxin

gneg lps; mediate interconnection between the OM and murein

lipoprotein

outer envelope; form small hydrophilic channels through the outer envelope allowing the diffusion of neutral charged solutes MW < 600 daltons; 3 identical units; associate to form membrane holes; transmembrane

porins

a separate compartment between the cell membrane and outer membrane in g neg bacteria; site of redox reactions, osmotic regulations, solute transport, protein secretion, hydrolysis

periplasm

usually composed of only 1 or a few subunits self organized into repeating structures, which can have hexagonal, tetragonal, or trimeric symmetry; forming a rigid yet permeable paracrystalline lattice

s-layers

another confirmatory tests for gram reactions; 3% KOH (lysing agent); gneg more susceptible due to thin lipid content in the OM

gregersen's method

uses carbolfuschin for primary stain; methylene blue for counterstain; for staining bacteria which cell wall contains high lipid concentrations thus are waxy, hydrophobic, and impermeable to gram staining; also for bacteria resistant to acid and alcohol (AFB and/or AAFB)

acid fast staining

small cell wall-less bacteria but possess distinct morphologies; have internal protein cytoskeleton that determines and maintains cell shape; cytoplasmic membrane are more stable than that of other bacteria due to sterols; uses lipoglycans to stabilize cell membrane; parasitic and pathogenic

mollicutes- mycoplasma. spiroplasma, acholeplasma

cytoplasmic membrane functions

serves as permeable barrier protein anchor for energy conversation lipid biosynthesis and cell wall protein secretion secretion and uptake of intracellular signals responses to environmental signals

major phospholipid in the cytoplasmic membrane; formed from glycerol-3-P, serine and fatty acids in the ratio 1:1:2

phosphatidylethanolamine

next most prevalent phospholipid in the cytoplasmic membrane; formed from glycerol-3-P and fatty acids in equimolar ratios

phosphatidylglycerol

cytoplasmic membrane components; embedded in the CM;amphipathic; bound to the fatty acids of the phospholipids via hydrophobic bonding

integral proteins

cytoplasmic membrane components; attached to membrane surfaces by ionic interactions

peripheral proteins

archaeal membrane distinction from bacterial and eukaryotic membranes

ether linkages isoprenoid side chains branched side chains

lipid monolayer composition examples in archaea

diglycerol tetraethers crenarchaeol

contains of aqueous solution of three groups of molecules- maromolecules (proteins, mRNA, tRNA etc), small molecules which serves as energy sources, precursors of macromolecules, metabolites or vitamins, various organic and inorganic ions and cofactors; structural components: nucleoid, ribosomes, inclusion bodies

cytoplasm

isolated compartments where specialized conditions are maintained to perform chemical process not possible in the cytoplasmic space (ie. anammoxosome, carboxysome, acidocalcisomes); densely packed membrane structures that facilitate higher throughput for membrane-dependent metabolic processes by increasing the available surface in a cell (ie thylakoid, chlorosome, membranous structure in methane, nitrite, and ammonia oxidizer)

intracytoplasmic membranes (ICM)

complex structures made of both protein and ribonucleic acid; present in the cytoplasmic matrix or loosely attached to the plasma membrane; site of protein synthesis

ribosomes

site of DNA and RNA synthesis; DNA tightly coiled; DNA binding 'nucleoid' proteins that bend and compact DNA

nucleoid

general term for the thick cover or layer of polymers deposited outside the cell

glycocalyx

well organized glycocalyx; attached firmly to the cell wall; compact; excludes particles like india ink

capsule

zone of diffused, unorganized material; loose association; does not exclude particles

slime layer

capsule staining procedure; use of acidic dye, nigrosin/ india ink; stains the background brownish to black; capsules clear zones or colorless around refractile cells

negative staining/ Duguid's method

capsule staining procedure; use of crystal violet as primary stain and 20% copper sulfate as decolorizer and counterstain; capsules appear light or blue or colorless, cells are dark purple

anthony's method

capsule staining procedure; uses congo red as ph indicator; stain component- 1% acid fuchsin which stains cell cytoplasm, 5% phenol which increases penetration power of stain, 30% FeCl3 which is a chemical fixative, 20% acetic acid which changes the background from red to blue

maneval's staining method

hairlike substructure on the surfaces of prokaryotic cell; composed of protein sub-units called 'pilins'

pili/fimbriae

types of pili; involved in attachment of cells to surfaces; composed of a single protein; major determinant of bacterial virulence; up to 1000 per cell

adhesion pili

types of pili; vehicles for transfer of genetic information between bacteria; composed of phosphoglycoprotein; about 1-10 per cell

conjugation pili

types of pili; structure for motility

type IV pili

distinct bodies that may occupy a substantial part of the cytoplasm; may be organic or inorganic; some lie free in the cytoplasm or enclosed by a shell consisting of proteins or a membranous structure composed of proteins and phospholipids; usually used for storage

inclusion bodies

motility structures and mechanisms; swimming in aqueous environment; swarming on solid surface

flagella

motility structures and mechanisms; twitching motility

type 4 pili

motility structures and mechanisms; swimming without flagella

cytoskeleton

motility structures and mechanisms; buoyancy; movement in water column

gas vesicle

flagellar composition; a hollow rigid cylinder constructed of a single protein called flagellin; consists of a thousand copies of flagellin

flagellar filament

flagellar composition; connects filament to cell; structurally related to filament, made of different protein, FLgE; less rigid than filament; junction proteins between hook and filament

flagellar hook

motile bacteria move in response to different environmental stimuli

taxis

unique about flagella of spirochetes

located in the periplasm function by rotating in the periplasmic space expressed throughout the cell's life cycle and are believed to have vital skeletal and motility functions leads into corkscrew motility

surface motility; requires ATP hydrolysis to extend to several micrometers and then retract the cell to move forward; movement occurs in discrete movements

twitching motility by type IV

surface motility; requires a helical intracellular protein track that interacts with the gliding motors and extracellular adhesion proteins; rotation driven by PMF that translate the force to the helical track causing adhesion protein to move in a helical pattern; results in a continuous forward motion and clockwise rotation of the cell

gliding motility

surface appendages; means tuft in latin; first identified functional amyloids; extracellular protein fibers produced by many enteric bacteria (E. coli, S. enterica); crucial in biofilm formation, colony patterning, and interactions with host factors; morphology is characterized by highly coiled and aggregative thin fibers randomly distributed on the cell surface; resistant to degradation by proteases and denaturation by detergents

bacterial curli

surface appendages; tubular surface appendages broadly found in gram-negative bacteria; extend without apparent connection to the cytoplasm and are attached to the cell surface by proteins; for long-distance communication among bacteria, mediating exchanges in intercellular signals; randomly distributed on the cell surface

bacterial spinae

surface appendages; hollow tubules; small reed or cane in latin; connects the cells of pyrodictium to each other; highly resistant to heat and denaturing agents; entered the periplasmic space but not the cytoplasm; function unclear whether used for nutrient and genetic exchange or provide a means for anchoring

archaeal cannulae

surface appendages; prickle, claw, hook, barb / fishing rod in latin; structurally resemble type IV pili except for their barbed terminus; affix cells to a surface to form a networked biofilm; function as miniature grappling hooks to attach cells to a surface or to one another; archaeal cells that bear these fibers are found in macroscopically visible string-of-pearls like arrangements among bacterial filaments

archaeal hami

anatomy of the spore; loosely cross-linked peptidoglycan

cortex

anatomy of the spore; forms complex with small acid-soluble proteins (SASP); binds to DNA and protects it from UV desiccation and dry heat; carbon and energy source for outgrowth of new vegetative cell during germination; contains high levels of dipicolinic acid and other ions; dehydrates the spore conferring resistance to chemicals and inactivates enzymes

core

anatomy of the spore; possesses ridges and valleys; appears as fold in cross-section (TEM); prevents entry of large degradative molecules, toxic small reactive molecules, and predation by other microbes; when unfolded accommodate the increase in volume of that accompanies germination

coat

anatomy of the spore; outermost layer of the spore; contiguous shell surrounding the coat, and separated from it by a gap (interface); proteins present are candidates for vaccine and spore detection and important interaction with the environment

exosporium

do not possess photosystem II, thus do not produce O2; do not fix CO2 thus, do not require carbohydrates and reductants from vegetative cells; do not divide; site of nitrogen fixation, nitrogen gas to ammonia

heterocysts in anabaena

Micro Physio Flashcards

(76 cards)