Ch 22 bacteria and archaea (prokaryotes)

describe prokaryotes :

first organisms on earth 3.5-3.8 BYA

ubiquitous

live on and in every other living organisms

most harmless and essential to all life

anoxic

no molecular oxygen

what organisms lived in the ancient atmosphere?

anerobic organisms

phototrophs

autotrophic organisms that convert solar energy into chemical energy

cyanobacteria

blue-green algae that evolved from simple phototrophs

what began oxygenation of the atmosphere?

ancestral cyanobacteria

what allowed the evolution of other life forms in the ancient atmosphere?

increase in O2 concentrations

what is the most abundant photosynthetic organism on Earth?

marine cyanobacteria, Prochlrococcus

extremophiles

adapted to grow under extreme conditions

deep see vent, heat, dry, cold, radiation

what are deinococcus radiodurans ?

prokaryotes that tolerate very high doses of ionizing radiation and heat

dead sea

hypersaline basin that is 10x saltier with 40x more magnesium than sea water

halophiles

prokaryotes that live in the dead sea that have divalent cations, are acidic, and have intense solar radiation

who discovered the techniques for pure culture including staining and growth media?

Robert Koch

culture medium

contains all the nutrients needed by the target microorganism and can be liquid(broth) or solid (agar)

what should there be after an incubation time at right temp in a culture medium?

evidence of microbial growth

pure culture

lab culture containing a single species of microorganism

what should agar of a person with strep look and why?

the agar should be clear bc strep lyses the red blood cells

colony

a visible mass of microorganisms originating from a single mother cell

incubation

maintaining controlled environmental conditions for the growth of bacteria

are prokaryotic or eukaryotic cells smaller?

prokaryotic cells

predominantly single-celled organisms of the domains bacteria and archaea are classified as…

prokaryotes

what 4 common structures do all cells have?

plasma membrane

cytoplasm

ds DNA genome

ribosomes

plasma membrane function

fxns as a barrier for the cell and separates cell from environment

cytoplasm

complex sol’n of organic molecules and salts inside cell

ds DNA genome

informational archive of the cell

ribosomes

sites of protein synthesis

pro and karyon mean?

before and nucleus

eu and karyon mean?

true and nucleus

what are the 3 main categories of shapes for prokaryotes?

cocci

bacilli

spirilli

cocci

spherical/round

bacilli

rod-shaped

spirilli

spiral-shaped

what can prokaryotes occur in when speaking of terms of shape?

pairs

chains

tetrads

clusters

what do prokaryotes not have in their structure?

membrane-bound organelles

nucleus (DNA in nucleoid)

microtubules

microtubules

mechanical support for cell division and movement

nuceloid region

region that contains DNA

plasmids

extra chromosomal DNA

pili

help w/attatchment

flagellum

help w/movement

what do the capsule, cell membrane, and cell wall do/ where are they?

capsule -outer

cell membrane-innermost

cell wall- middle and give structural support to protect from lysis

what features aren’t found in all prokaryotes?

flagella, capsules, and pili

is archaea closer related to eukarya or bacteria?

eukarya

what are the gram negative bacteria?

proteobacteria

chlamydias

spirochetes

cyanobacteria

what are eukaryotic mitochondria thought to be derived from?

proteobacteria

proteobacteria

includes N-fixing bacteria and common gastrointestinal pathogens like food poisoning

what are examples of proteobacteria?

escherichia coli

salmonella(food poisoning)

vibrio cholerae (diarrheal illness)

chlamydia

all are endoparasites (live w/in animal cells)

what does chlamydia cause?

eye infection or pneumonia in children of infected women

pelvic inflammatory disease, leads to infertility

what is chlamydia preventable or curable by?

antibiotics

spirochetes

spiral shape and free-living that include disease-causing pathogens

what an example of a spirochete ?

syphilis (STD)

what is the causative agent of syphilis?

traponema pallidum

what is another example of a spirochete?

lyme disease which is fever and skin rash

what bacteria causes lyme disease?

Borrelia burgdorferi

vector

carry a disease from an infected animal to another who is uninfected

cyanobacteria

plant-like, O2 generating photosynthesis and some are N-fixers

N-fixers

convert nitrogen gas N2 to ammonia NH3

heterocyst

specialized nitrogen fixing cells that fix nitrogen that is used for growth of cyanobacteria

what does cyanobacteria do to make toxins ?

blooms

gram-positive bacteria

include decomposers in soils and pathogens

what an example of gram-positive bacteria?

Bacillus anthracis

decomposers

break down dead organic material in the soil into CO2, H2O, nitrogen, phosphorus

what do tetanus shots protect us from?

Clostridium tetani

what is MRSA resistant to?

meticicllin which is spread by skin to skin contact

what causes skin infection?

staphylococcus areus

what does streptococcus cause?

strep throat and scarlet fever

what does the domain archaea include ?

extremophiles and methanogens, but they may live in normal conditions

are there any human disease causing archaeans ?

no

methanogens produce what?

methane CH4 as a by product of anaerobic respiration

what does the prokaryotic plasma membrane do?

controls what goes in and out of the cell

selectively permeable

keeps ions, proteins, and other molecules w/in cell preventing diffusion into extra cellular environment

what’s the structure of the plasma membrane ?

phospholipid bliayer composed of 2 layers of lipid molecules

bacterial membrane

fatty acids linked to glycerol

arcaheal membrane

branched isoprene chains linked to glycerol

what are the 2 differences between a phospholipid from archaea vs one from bacteria and eukarya?

archaea have an ether linkage while bacteria and eukarya have an ester linkage

archeas is joined tg bacteria and eukarya is not

what does gram strain reflect ?

cell wall type

gram +(pos.) bacteria

bacteria w/thick peptidoglycan layer

what does gram + bacteria stain?

purple

gram stain

based on differences in cell wall and structure of bacteria

who invented gram stain and when did they?

Hans Christian Gram in 1882

what percent of the wall is peptidoglycan and what is the leftover made of in gram + bacteria ?

90 and the leftover is Teichoic acid

gram -(neg.) bacteria

bacteria w/thinner peptidoglycan plus an outer lipopolysaccharide bilayer membrane

what are characteristics of the lipopolysaccharide layer?

it is toxic, resists drugs, and immune system

what does gram + bacteria stain?

pink

how much of the cell wall is peptidoglycan in gram - bacteria?

10%

what is a gram - bacteria?

safranin which is pink

what is a characteristic describe the prokaryote structure?

many have a capsule or slime layer

do prokaryotes secrete sticky carbs & proteins out cell wall ?

yes

what do prokaryotes glue tg or glue to?

they glue tg cells or to the surface

what do prokaryotes resist ?

attack from immune system

what do prokaryotes hold in?

moisture

what is significant abt nostoc filaments?

they are held tg by slime and make a easily visible mass

what are all hairlike structures of prokaryotes and what do they do?

flagellum (multiple flagella) that act as an organelle for motility and extension

fimbriae

hair-like protein that are short pilli which help cells stick to surfaces and each other

what can prokaryotes form?

a sex pillus which is a mating bridge for a type of HGT

pili

pull 2 bacteria cells tg for DNA transfer (conjugation)