domains of prokaryotes

divided into 2 domains: bacteria (eubacteria) and archae-bacteria

prokaryotes (bacteria): oldest organism

fossiles of prokaryotes from 2.5 bya (euks only 1.5 bya)

eu = true / common

-cell walls have petidoglycan

-archae - ancient, but not as old as eubacteria

-cell walls lack peptidoglycan

-mRNA translation more like Eukaryotes

-live in extreme environments

-DNA/RNA sequence

-cell wall chemistry

-type of photosynthetic pigments

-metabolic pathways

-b/c they've been evolving for 2.5 billion years

-very short generation time, reproduce very quickly so even more diversity

-make their own food

-bottom of the food chain (producers)

1)photoautotrophs (plant like photosynthesizers)

2)chemoautotrophs (use chemical energy rather than light energy)

-don't take in organic molecules

higher in the food chain (consumers)

-take in complex organic molecules for energy (contain Carbon)

1)photoheterotrophs - use light for energy but take in organic C

2)saprophytes - absorb dead organic matter (like a fungus)

3)parasites - absorb or ingest host tissues (host is alive)

4)commensals - like parasite but don't harm host

5) mutualistic symbionts - see other card

type of heterotrophic prokaryote

-N₂-fixing bacteria in plant root nodules

-bacteria inhabiting gut of animals (especially ruminants)

light producing bacteria in some animals (flourescent)

are there predator/herbivore bacteria?

no

too small (only one cell)

-a predator eats whole organism

-an herbivore eats whole plant

chew their cud

-cows eat, bring it back up, chew more

symbiosis and types of symbiosis

-a close association b/w two or more organisms

1)mutualism - both organisms benefit

2) parasitism - one benefits / one is harmed

3)commensalism - one benefitted, one neither harmed nor helped

no membrane bound organelles

-smaller ribosomes

-cell wall outside cell membrane

-no nucleus: chromosomes free in cytoplasm

-no mitochondria

-no endoplasmic reticulum

-no golgi apparatus

-no chloroplasts

-no lysozomes

-all have a cell wall

-some have flagella / pili

-cytoplasm

-ribosomes

-nucleoid

-internal membranes (for CR or PS)

much smaller than eukaryotes (in general)

-some almost as small as viruses

-rarely can some be bigger than eukaryotes

1.Coccus: spehrical (chains or clusters)

2.Bacillus: Cylindrical/rod shaped (in or gut and help with digestion)

3. Spirillum: helical, coiled

1)plants: cellulos

2)fungi: chitin

-1 and 2 not bacteria

3)bacteria: peptidoglycan, polysaccharides, amino acids

-are either gram positive or gram negative

gram positive: have Plasma Membrane (PM) and cell wall that is exposed

-thick peptidoglycan wall that interacts with Gram's stain (stains purple)

gram negative: have PM, cell wall, and outer membrane

-thin, sandwiched peptidoglycan layer (between outer membrane and PM

-doesn't bind well with Gram's stain (stains red)

this is a "resting cell"

-form inside cell with just DNA and essentials

-have thick, protective walls = spore coat

-can survive freezing, drying, boiling, etc...

(eubacteria) Cell movement

many are motile b/c need to get to food / light (energy) and to avoid bad environment

-helical flagella (true flagella), like a rotor

-eukaryotes  have a different type of flagella

glide along on slime

-no flagella, not known how they move

-from spore-releasing fruiting bodies

eubacteria reproduction

both sexual and asexual, not sexual like humans

-lack nuclei, but have chromosome in area called nucleoid

-reproduce by binary fission (asexual), other asexual means, or sexually

double stranded DNA

-circular, attached to inside of membrane

-results in 2 identical cells 

-DNA polymerase allows it to reproduce its cells 

-asexual 

-not as complicated as mitosis

-enormous reproductive potential

-once every 20 min in ideal conditions)

-every 6 hours, 500,000 offspring

-24 hours 2x10⁶ kg of bacteria, all identical, except for mutations

Conjugation

transformation

transduction

donor cell gives part of chromosome to recipient

-uses pili or cytoplasmic bridges

DNA fragments carried by virus from one bacteria to another

-general: when bacteria produces new bacteriophages during lytic cycle, some bacteriophages have only bacteria DNA not virus DNA

-specialized: VDNA and bacteria DNA incorporated into bacteriophage. bacteria DNA that is incorporated is close to VDNA 

can pass on drug resistance from one bacteria to another

-exploited by molecular geneticists (especially transduction)

Louis Pasteur

showed that bacilli caused anthrax in sheep, humans, and cows

-showed that bacilli caused TB in humans

Louis Pasteur

Joseph Lister

Robert Koch

bubonic plague, TB, dental caries, Strep throat

-cause illness by:

a)feeding on and destroy host tissue

b)interfering with host tissues because of sheer numbers

c)produce toxins

-use same antibiotics for millions of patients

-use antibiotics indiscriminately

-keep susceptible hosts together for cross contamination

-keep bacterial infections near hosts with weakened immune system

-outnumber harmful ones

a) N fixers (roots of plants)

b) decomposers (break down dead material)

c) fermentations (beer, yogurt, cheese)

d) manufacturing (vinegar, vitamins)

e) antibiotic (streptomycin)

f) genetic engineering (insulin, eat oil spills)

occupy challenging habitats

-cell walls don't have peptidoglycan

-mRNA different, translation (to proteins)

more like eukaryotes

methanogens

type of archaebacteria 

-produce methane (CH₄)

gut symbionts - type of this, located in guts, digest cellulose in cows

-also located in: deep sea thermal vents, O₂ poor bogs and marshes (feed on decaying vegetation), lots of other places

halophiles

 type of archaebacteria

-live in very salty environments (death valley, Dead Sea)

-environment often high in pH

-photosynthesizers

type of Archaebacteria

-high temperature tolerance

-located in volcanic vents

(reduction = add Hydrogen), because hydrogen has electrons...(not really sure why this is included with this type of archabacteria)

type of archaebacteria

-oxidize sulfer (adding hydrogen and oxygen)

-can withstand high temp AND very low pH (acidic)

-located in volcanic vents, hot sulfur springs, hydrothermal vents  (deep sea)

-only organism that can create organic material from non-organic sulfides without PS

Hydrothermal vents

produce chemicals which thermoacidophiles use to power production of organic materials from non-organic materials

cell walls and enzymes modified to function in high temps and pressures, extreme pH, etc.

 -DNA transcription/translation work at high temps

-PCR machine uses DNA polymerase from thermoacidophiles to make more copies of DNA faster at high temps (cuts apart DNA and helps it copy)