BIO102: Chapter 27: Archaea and Bacteria

archaea have distinctive membrane phospholipids that are formed with _______ _______, while ester bonds make up the membrane phospholipids of bacteria and eukaryotes

- ether bonds

describe episilon proteobacteria

- examples include helicobacter pylori

describe delta proteobacteria

- examples include myxobacteria and bdellovibrios

how do aerotolerant anaerobes get their energy

- fermentation - anaerobic respiration

what are some examples of obligate anaerobes

- firmicutes genus Clostridium

prokaryotic species differ in number and location of ________. how can these structures occur

- flagella - as singly, or in tufts at one pole or may emerge from around the cell

what is a pro of biofilms

- forming them helps microbes remain in favorable locations for growth

define vertical evolution

- gene transfer occurs often from parent to progeny *no interference*

many bacteria exude a coat of slimy mucilage called.....

- glycocalyx, capsule, or extracellular polymeric substance (EPS)

bacteria having chemically different walls are called ______ _______ or ________ ________ after the staining process used to distinguish them

- gram-positive - gram-negative

what are some characteristics of the phyla Actinobacteria

- gram-positive bacteria producing branched filaments - many form spores - notable antibiotic producers(over 500 different antibioticsc known from this group) - some fix nitrogen in association with plants

how have gram negative bacteria adapted to the presence of an outer envelope

- has several types of protein systems that function in secretion

what other roles does mucilage play a part in

- holding cells together closely enough for chemical communication and DNA exchange to occur - helping aquatic species to float in water - binding mineral nutrients - repelling attack

what are some characteristics of Lokiarchaeota

- identified from deep ocean samples - closely related to eukaryotes

what are the enviromental and medical importance of biofilms

- in aquatic and terrestrial environments they stabalize and enrich sand and soil surfaces - important in formation of mineral deposits - dental plaque is an example of bad biofilm - can develop in industrial pipelines where it can corrode metal surfaces

what are some characteristics of Crenarchaeota

- includes organisms that live in extremely cold or hot habitats - some are widespread in aquatic and terrestrial habitats

what are some characteristics of the phyla Bacteroidetes

- includes representatives of diverse metabolism types, *(some are common in the human intestinal tract and others are primarily aquatic)*

what kind of effect do archaea's and bacteria's metabolic processes have on a global scale

- influence earth's climate - atmospheres - soils - water quality - human health and technology

how are endospores produced

- inside bacterial cells by the enclosure of DNA and other materials within a tough coat, and then are released when the enclosing cell dies and breaks down.

what are some characteristics of the phyla Chloroflexi

- known as the green nonsulfur bacteria - conduct photosynthesis without releasing oxygen

define akinetes

- large, food-filled cells that can survive in winter - produced by aquatic filamentous cyanobacteria

the __________ _________ outer envelope of gram negative bacteria helps them to resist the entry of some antibiotics but on the verse impedes secretions of _______from bacterial cells into the environment, a process that normally allows cells to communicate with each other

- lipopolysaccharide rich - proteins

what does Borrelia burgdorferi cause

- lyme disease

in other bacteria, plasma membrane ingrowth has generated additional intriguing adaptations like....

- magnetosomes - nucleus like bodies/bacterial organelles

in what bacteria do magnetosomes occur in

- magnetospirillum and its related genera

what are the functions of a cell wall

- maintain cell shape and help protect against attack by viruses or predatory bacteria - help microbes avoid lysing in hypotonic conditions

what are some characteristics of the phyla Spirochaetes

- motile bacteria having distinctive corkscrew shapes with flagella held close to the body - include pathogens Treponema pallidum(agent of syphilis) and Borrelia burgdorferi(causes lyme disease)

some cyanobacteria display ____________, like cellular attachment, specialized cells, intercellular chemical communication, and apoptosis

- multicellularity

define chemoheterotrophs

- must obtain organic molecules for both energy and as a carbon source

what are some characteristics of the phyla Chlamydiae

- notably tiny, obligate intracellular parasites - some cause eye disease in newborns or sexually transmitted diseases

what do the domains Archaea and Bacteria consist of?

- of microorganisms whose cells have a prokaryotic structure - ex: lack nuclei with porous envelopes and other structures that eukaryotes have

define autotrophs

- organisms that are able to produce all or most of their own organic compounds from inorganic sources

define extremophiles

- organisms that occur primarily in extreme habitats

define heterotroph

- organisms that require at least one organic compound and often more from their environment

what are some characteristics of the phyla Cyanobacteria

- oxygen producing photosynthetic bacteria (some capable of anoxygenic photosynthesis) - photosynthetic pigments include chlorophyll a and phycobilins - can occur as unicells, colonies, unbranched filaments, and branched filaments - in waters having excess nutrients, blooms may be produced and may release toxins harmful to the health of humans and wild domesticated animals

the domain archaea and bacteria are termed a _______ group

- paraphyletic

what are injectosomes

- pathogenic bacteria have developed needle-like systems made of components found in flagella that inject proteins into animal or plant cells as part of the infection process *type III secretion systems*

bacterial cell walls occur in two major forms that differ in ________ ______, _________ ________, and response to __________

- peptidoglycan thickness - staining properties - antibiotics

the outer envelope of gram negative bacteria is a _________ ________, but distinct from the plasma membrane

- phospholipid bilayer

what two categories can autotrophs be broken down into

- photoautotroph - chemoautotroph

what are two subcategories of heterotrophs

- photoheterotrophs - chemoheterotrophs

define obligate anaerobes

- poisoned by molecular oxygen

what are some characteristics of Korarchaeota

- primarily known from DNA sequences found in samples from hotsprings

what key ecological roles do bacteria and archaea play

- producing and breaking down organic carbon - acting as beneficial symbionts in plants and animals - act as disease agents

some archael cells lack cell walls most possess a wall composed of _______

- protein

give some examples of organisms that do nitrogen fixation

- proteobacteria of the genus Rhizobium

what are the categories of extremophiles

- psychrophiles - thermophiles - radioresistant microbes - alkaliphiles - acidophiles - halophiles - xerophiles - barophiles - endoliths

what are some characteristics of the phyla Planctomycetes

- reproduce by budding rather than binary fission - cell wall lacks peptidoglycan - cytoplasm may contain nucleus-like bodies - endocytosis may occur

define obligate aerobes

- require oxygen gas (molecular oxygen) in order to survive

what are some characteristics of ether bonds

- resistant to damage by heat and other extreme conditions

describe archaeal flagella

- rotate but are much thinner than bacterial flagella - powered by hydrolysis of ATP

diverse archaea occupy habitats with very high _______ ________, ________, _________ _________ or __________ that would kill most bacteria and eukaryotes

- salt content - acidity - methane levels - temperatures

what is another name for decomposers

- saprobes

describe gamma proteobacteria

- some examples include neisseria gonorrhoeae, vibrio cholerae, salmonella enterica, and escherichia coli

how is FtsZ used in binary fission

- squeezes dividing cells into two progeny cells

where do methanogens live

- swampy wetlands - deep sea habitats - subsurface arctic deposits

what research is behind the human microbiome

- that humans have inherited gut microbes from primates through extensive horizontal gene transfer

describe beta proteobacteria

- the genus is nitrosomonas, a soil inhabitant important in the global nitrogen cycle is a prime example

what does the endosymbiosis theory propose

- the mitochondria and chloroplasts of eukaryotic cells originated from alpha proteobacteria and cyanobacteria respectively by endosymbiosis. *in this case, endosymbiosis resulted in the horizontal transfer of many genes from bacterial genomes to eukaryotic nuclei* - chloroplasts and mitochondria cannot reproduce outside the host eukaryotic cells

what do archaea help biologist understand....

- the origin of life - origin of eukaryotes - how life on earth has evolved in extreme environments - what kinds of extraterrestrial life might exist

what does the koch postulates states and what is the reason for its use

- the presence of suspected pathogen must correlate with occurrence of symptoms - pathogen must be isolated from infected cell and grown in pure culture if possible - cells from pure culture show cause disease when inoculated into a healthy host - same pathogen show be isolatable from the second infected host *used to determine whether a particular organism causes a specific disease*

define horizontal gene transfer

- the process in which an organisms receives genetic material from another organism without being the offspring of that organism

define nitrogen fixation

- the removal of nitrogen from the gaseous phase is called fixation

if a bacteria is gram-positive they will have walls that are relatively _________ _______ __________. what phyla(s) of bacteria are gram positive

- thick peptidoglycan layer - firmicutes and actinobacteria

if a bacteria is gram-negative they will have walls with a ________ ______ of ________ enclosed by a thin, outer envelope whose outer leaflet is rich in ___________

- thinner layer of peptidoglycan - lipopolysaccharides

what is an example of a facultative anaerobe

- thiomargarita namibiensis

what are magnetosomes

- tiny crystals of an iron mineral known as magnetite, each surrounded by a membrane - help bacteria orient themselves in space and thereby locate the submerged, low oxygen habitats that they prefer

horizontal gene transfer can occur between two different bacterial species via _________, ___________, and ____________

- transduction - transformation - conjugation

what is another way to detect and count prokaryotic cells

- treat samples with a stain that binds bacterial DNA causing cells to glow brightly when illuminated with UV light *called the fluoresence method*

define chemoautotroph

- use energy obtained by chemical modification of inorganic compounds to synthesize organic compounds - ex: nitrification, oxidation of sulfur, iron or hydrogen

define photoautotroph

- use light as a source of energy for the synthesis of organic compounds from CO2 and H2O or from H2S

describe bioremediation

- used to reduce levels of harmful materials in the environment

what are some characteristics of the phyla proteobacteria

- very large group of gram-negative bacteria(collectively having high metabolic diversity) - include many species important to medicine, agriculuture and industry -

what are some characteristics of Thaumarchaeota

- widespread in terrestrial and aquatic environments - has species that oxidize ammonia (important in global nitrogen cycling)

what are some examples of bacteria with injectosomes that allow them to attack human cells

- yersinia pestis (agent of bubonic plague) - salmonella enterica (food poisoning called salmonellosis) - burkholderia pseudomallei (cause of meliodosis)

what does Treponema pallidum cause

agent of syphilis

what are methanogens

anaerobic archaea that convert CO2, methyl groups or acetate to methane and release methane from their cells into the atmosphere

the chloroplasts of eukaryotic algae and plants were derived from _____________

cyanobacteria

what is the only bacteria known to generate oxygen as a product of photosynthesis

cyanobacteria

_________ __________ determine cell shape

cytoskeletal proteins

what kind of movement does a pili provide

directional movement toward food materials

what are aerotolerant anaerobes

do not use oxygen but are not poisoned by it either

________ can remain alive, although in a dormant state for long periods of time and reactivate when conditions are suitable

endospores

horizontal gene transfer can also occur via _____________

endosymbiosis

organisms classified in the domain archaea share a number of features with those classified in ______________, suggesting a common ancestry

eukarya

small cell size limits the amount of materials that can be stored within cells but will allow ______ cell division

faster

define halophiles

species able to grow in higher than usual salt concentrations

many bacteria form __________ __________ with eukaryotes and are thus of concern in medicine and agriculture

symbiotic associations

what is Mycobacterium tuberculosis in reference to humans

the agent of tuberculosis

define endosymbiosis

the process in which one species lives in the body of another species

define horizontal gene transfer

the transfer of genes between different species

some other gram-negative bacteria pathogens used a _________ _________ secretion system to deliver toxins or DNA into cells

type IV

what way do bacteria and archaeal species reproduce

via binary fission

what is anoxygenic photosynthesis

when an organism photosynthesizes but no oxygen is released

what are some characteristics of euryarchaeota

- early diverging euryarchaeota include some hyperthermophiles, diverse methane producers, and extreme halophiles

what are some examples of Proteobacteria

- Agrobacterium tumifaciens - Escherichia coli - Haemophilus influenzae

the phyla's ________ and _________ are particulary diverse and relevant to eukaryotic cell evolution, global ecology and human affairs

- Cyanobacteria - Proteobacteria

what are the three domains of life

- Eukarya - Archaea - Bacteria

name 10 major phyla's of the domain bacteria

- Firmicutes - Bacteroidetes - Chlamydiae - Planctomycetes - Spirochaetes - Actinobacteria - Chloroflexi - Deinococcus and Thermus - Cyanobacteria - Proteobacteria

name some phyla of the domain archaea

- Lokiarchaeota - Korarchaeota - Thaumarchaeota - Crenarchaeota - Euryarchaeota

what is an example of the phyla Actinobacteria

- Mycobacterium tuberculosis

what is myxococcus xanthus

- a gram negative bacterium that is able to glide across surfaces, forming swarms of thousands of cells - this behavior aids feeding by concentrating digestive enzymes secreted by the bacteria and when food is scarce the swarms form tiny tree-shaped structures from which tough spores disperse, by this means cells move to new, food rich places - part of the phyla Proteobacteria

what are some characteristics of a methanopyrus

- a methane producer - an example of an hyperthermophile( a subcategory of extremophile) - grows best at deep sea vents (98 degrees celsius) - cannot grow in temperature less than 84 degress celsius

define quorum sensing

- a process that fosters biofilm formation - individual microbes secrete small molecules having the potential to influence the behavior of nearby microbes, if enough present signalling molecules build up to cause a collective behavior

what are photoheterotrophs

- able to use light energy to generate ATP but they must take in organic compounds from the environment as a source of carbon

what does neisseria gonorrhoeae cause

- agent of disease gonorrhea

describe biofilms

- aggregations of microorganisms that secrete adhesive mucilage, thereby gluing themselves to surfaces

genera of the phyla proteobacteria can be broken down into five major subgroups, what are they?

- alpha - beta - gamma - delta - epsilon

define symbiosis

- an organism that lives in close association with one or more other organisms

describe alpha proteobacteria

- ancestors of mitochondria - Rhizobium and other related genera of this category form mutually beneficial associations with the roots of legume plants - agrobacterium

what does the domain Eukarya consist of

- animals, plants, fungi, and protists

what is an example of chemoautotroph

- archaea of the genus sulfolobus

what are some characteristics of the phyla Deinococcus and Thermus

- are extremophiles - the genus Deinococcus is known for high resistance to ionizing radiation and the genus thermus means inhabits hot springs

cyanobacteria display the greatest body of diversity found among the bacterial phyla, name some forms they occur in.

- as single cells called unicells - as colonies of cells held together by thick, gluey substance called mucilage - form filaments of cells that are attached end-to-end (including filaments that branch)

what is an example of photoheterotrophs

- bacteria in the phyla chloroflexi

describe Gemmata obscuriglobus

- bacteria with nucleus like bodies/bacterial organelles

why are cyanobacteria named as such

- because they have photosynthetic pigments called phycobilins that help chlorophyll absorb light energy giving cyanobacteria a blue-green hue

describe bacterial flagellum

- built of about 30 proteins - lack plasma membrane covering - internal cytoskeleton of microtubules made of tubulin - lack motor protein dynein - spin, propelled by molecular machines composed of a filament, hook and motor - powered by the movement of hydrogen ions (electron transport chain)

how do pathogenic bacteria attack cells

- by binding to the surface of healthy cells and injecting substances that help them utilize cellular components

describe what bacterial organelle/nucleus like body is?

- can isolate DNA in a simplistic membrane

define facultative anaerobes

- can use oxygen via aerobic respiration, obtain energy via anaerobic fermentation, or use inorganic chemical reactions to obtain energy

what does agrobacterium tumifaciens do

- causes destructive cancer-like tumors called galls to develop on susceptible plants - caused by injecting its DNA into the plant cells

what does helicobacter pylori do?

- causes stomach ulcers

describe methotrophs

- certain bacteria that consume methane, thereby reducing its concentration in the atmosphere

what does vibrio cholerae cause

- cholera epidemics through contaminated water

what are the five common shapes that prokaryotic cells can occur in?

- cocci (spheres) - bacilli (elongated rods) - vibrios (comma shaped cells) - spirochaetes (spiral shaped cells that are either flexible) - spirilli (spiral shaped cells that are rigid)

what is peptidoglycan

- composed of carbohydrates that are cross-linked by peptides

describe mucilage

- composed of hydrated polysaccharides and proteins as well as lipids and nucleic acids

what is an example of photoautotrophs

- cyanobacteria

give some examples of producers

- cyanobacteria - autotrophic bacteria

what are some phyla(s) of bacteria that are gram negative

- cyanobacteria - proteobacteria

what are some characteristics of the phyla Firmicutes

- diverse gram-positive bacteria, some of which produce endospores - an example is the disease causing Clostridium difficile

many filamentous species produce specialized cells like....

- dormant akinetes and heterocytes in which nitrogen fixation occurs

what do myxobacteria and bdellovibrios proteobacteria do

- drill through the cells walls of other bacteria in order to consume them

bacterial binary fission generally requires a protein known as _________, which is related to the tubulin that make up eukaryotic microtubules

FtsZ

many bacteria are able to break down __________ for use as a source of organic carbon

antibiotics

horizontal gene transfer is common among _________ and _________

archaea and bacteria

what domain(s) are the most abundants and smallest known cells found on earth

archaea and bacteria

______ _______ is the basis of a widely used method for detecting and counting bacteria in food, water samples, or patients' body fluids

binary fission

a ________ helps some disease bacteria evade the defensive system of their host

capsule

most prokaryotic cells have a _______ _______

cell wall

______ _________ is an important component of bacterial function in nature

cellular shape

horizontal gene transfer affects __________ __________

genetic diversity

the ability to produce endospores allows some ______ _______ bacteria in the phylum firmicutes to cause serious diseases

gram positive

many cyanobacteria generate low oxygen conditions in specialized cells known as ________, allowing nitrogen fixation to occur in these cells

heterocytes

archaea use __________ chains instead of fatty acid chains in their membranes

isoprene

oxygen can poison nitrogenase, so most nitrogen fixers conduct nitrogen fixation in _____ ______ _______

low oxygen conditions

what is meant by gram negative bacteria?

mean they have a thinner layer of peptidoglycan and won't stain as much

what is meant by gram positive bacteria?

means it has a thicker layer of peptidoglycan thus penicillin(or any strong antibiotic) can kill it more than it could a gram negative.

define pathogens

microorganisms that cause disease in one or more types of host organism

although some members of domain bacteria live in extreme conditions, most favor ___________ conditions

moderate

if symbiotic association is beneficial to both partners the interaction is known as __________

mutualism

most prokaryotes are _______ _______

obligate aerobes

define paraphyletic group

one that does not include all the descendants of a single common ancestor

define acidophiles

organisms capable of surviving in highly acidic environments (pH of below 2)

define radioresistant microbes

organisms that can survive extreme exposure to radiation

define barophiles

organisms that can survive in highly pressurized environments

define xerophiles

organisms that can survive in very dry environments

define alkaliphiles

organisms with the ability to survive in environments capable of neutralizing strong acids (base environments with a pH from 9-11)

define psychrophiles

organisms with the ability to survive in extreme cold temperatures (starting below -4 degrees farenheit)

define thermophiles

organisms with the ability to survive in extreme heat temperature (above 140 degrees farenheit)

define endoliths

organisms with the ability to survive within solid rocks or deep in the earths' crust

if one partner in symbiosis benefits at the expense of the other the association is termed ______

parasitism

bacterial cells wall are made of ____________

peptidoglycan

_________ ________ ________ coat some bacterial filaments helping to prevent UV damage

pigmented slime sheaths

what do phycobilins give to cells

pigments them a blue-green color

some prokaryotic species have ______

pili

archaea and eukarya share more than 30 __________ _________ that are not present in bacteria

ribosomal proteins