Chapter 22: Prokaryotes: Bacteria and Archaea

prokaryotes

unicellular microorganisms

prokaryotes have an absence of what cellular structures

nucleus and membrane-bound organelles

prokaryotes have a presence of what cell structure

cell wall

what are the domains of prokaryotes?

bacteria and archaea

between Archaea and Eukaryotes, what three biological processes are similar?

transcription, translation, and DNA packaging

between Archaea and Bacteria, what is chemically different?

cell wall structure

prokaryotes can survive in what types of conditions

the same as humans (e.g., on phones) or extreme (e.g., volcanoes)

what percentage of prokaryotic species has been characterized?

0.8%

3.5 billion years, ago, Earth's atmosphere was high in CO2 and low in O2. this mean the atmosphere was ___?

axonic

microbial mat

multi-layered sheet of prokaryotes (mostly bacteria, some archaea)

what areas are microbial mats found in?

hot spring interfaces, deep-sea vents, hyper saline lakes, and marine estuaries

Early prokaryotes likely received energy from chemicals found near ___

hydrothermal vents

stromatolite

sediment formed from precipitated minerals by prokaryotes in microbial mat

stromatolite shows that bacteria and archaea

lived together and helped each other in microbial mats

Cyanobacteria (green algae)

autotrophs that convert solar energy into chemical energy, releasing O2

cyanobacteria contributed to what period when many organisms died?

great oxygenation (increase in atmospheric O2)

cyanobacteria causes what in fresh water?

algae blooms

extremophiles

bacteria and algae that adapted to grow under extreme conditions

acidophiles are a type of extremophiles that have optimal growth in ___?

pH 3 or below

alkaliphiles are a type of extremophiles that have optimal growth in ___?

pH 9 or above

thermophiles are a type of extremophiles that have optimal growth in ___?

60-80°C (140-176°F)

hyperthermophiles are a type of extremophiles that have optimal growth in ___?

80-122°C (176-250°F)

psychrophiles are a type of extremophiles that have optimal growth in ___?

-15-10°C (5-50°F) or lower

halophiles are a type of extremophiles found in areas with a ___

salt concentration of 0.2M or more

many halophiles are found in the Great Salt Lakes, where they produce a ___

pink pigment

Hadobacteria is a phylum in the ___

eubacteria kingdom

Thermus aquaticus is a type of Hadobacteria that grows best at ___

65-70°C (149-158°F), surviving at 50-80°C (122-176°F)

Deinococcus radiodurans is a type of Hadobacteria that survives high radiation levels, which is referred to as

radioresistant

Deinococcus radiodurans can consume ___, but they don't prefer ___

nuclear waste and other toxic material, extreme conditions

prokaryotes are cultured in a ___, which contains all necessary nutrients (in 37°C)

medium

broth medium

liquid with minerals and nutrients

agar plate medium

gelatin-like substance from red seaweed made of polysaccharides

over 99% of bacteria and archaea’s optimal growth conditions are unknown to us, or difficult to replicate. this means they are ___

unculturable

intercellular parasite

microorganisms capable of growing and reproducing in a host cell (e.g., N. gonorrhoeae)

biofilm

microbial community held together by the extracellular matrix (ECM)

the ECM is made of complex ___ and ___ secreted by microbes

carbohydrates, proteins

the ECM is located ___, and it holds ___

outside the cell; the cell together

stage one of biofilm formation is initial attachment (reversible), during which ___

bacteria weakly adhere to flat surface

stage two of biofilm formation is irreversible attachment, during which ___

bacteria attach to surface via pili

stage three of biofilm formation is maturation 1 during which ___

bacteria cells divide and grow, secreting the ECM. to form large and strong structures

stage four of biofilm formation is maturation 2, during which ___

cells continue to divide; ECM is much stronger

stage five of biofilm formation is dispersal, during which ___

sections of the ECM break to release bacteria so they can find another surface to repeat the process

prokaryotes are classified based on what two properties/structures?

cell shape (prior to genetic testing) and cell wall (NOT cell membrane)

cocci (coccus)

spherical cell shape

bacilli (bacillus)

rod-like cell shape

spirilli (spirillus)

corkscrew cell shape

if a prokaryote has a gram positive cell wall, this means it has a ___ peptidoglycan wall, and it will stain ___

thick, blue/purple

if a prokaryote has a gram negative cell wall, this means it has a ___ peptidoglycan wall, and it will stain ___

thin, pink/red

unlike bacteria, archaea do not possess

peptidoglycan walls

archaea with a psuedopeptidoglycan cell wall can’t be differentiated from gram positive bacteria because they ___

will also stain gram positive

other cell walls possessed by archaea include ___

polysaccharides, glycoproteins, and protein-based

ALL prokaryotes have which characteristics?

single cell with a singular piece of circular DNA, nucleoid area, cell wall outside the plasma membrane

SOME prokaryotes have which characteristics?

capsule, pili, and flagellum

capsule

additional layer of protection outside the cell wall

pili

helps with locomotion and reproduction

flagellum

tiny motor used for locomotion in liquids

bacteria have a lipid ___ membrane only, whereas archaea can have ____

bilayer, bilayer and monolayer

prokaryotes asexually reproduce via ___, during which the parent cell divides into 2 identical daughter cells

binary fission

what are two key components of binary fission?

it’s similar, but simpler, to mitosis, and it’s not an opportunity for genetic recombination or diversity

prokaryotes increase genetic diversity via ___

transformation and conjugation

transformation

cell randomly takes up prokaryotic DNA in the environment

conjugation

DNA is transferred between cells via sexual pili (mating bridge), which connects the cells

pathogen

microorganisms causing disease or illness to its host (e.g., M. tuberculosis [TB], Y. pestis [Plague]

few bacteria are pathogens. those that are use liv human cells for ___

energy and raw materials

very few pathogenic archaea are found in nature. they have ____ so they don’t needs humans

good metabolisms

bacteria are beneficial for which environmental processes?

carbon cycle (up-taking CO₂ from dead organisms) and nitrogen cycle (fixing nitrogen gas (N₂) to ammonia (N₃) for plant absorption, and N₃ to nitrates NO₃^-)

4 ways bacteria are use by humans are

in milk (s.lactis), cheese (s. creminis), wine (oenococcus oeni) and our microbiome

through recombinant DNA, E. coli can be helpful for ___

developing insulin

the microbiome is associated with ___ and ___

overall health, resistance to certain diseases (e.g., cancer)

antibiotic

chemical produced by microbes or synthetically, that’s hostile to bacteria growth

superbug are ___, which is caused by ___

antibiotic resistant bacteria, excessive antibiotic use resulting in the natural selection of resistant bacteria forms

during step 1 of antibiotic resistant, few germs are ___

drug resistant

during step 2 of antibiotic resistant, antibiotics kill both ___, which happens by change or not all all depending on how the bacteria enters the body

pathogens and good bacteria protecting the body

during step 3 of antibiotic resistant, drug resistant bacteria survive, and now ___

grow and take over

during step 4 of antibiotic resistant, drug resistant bacteria transfer their characteristics to ___

other bacteria via binary fissure

good antibiotics only ___

attack bacteria cells