Exam 4 Flashcards by Sierra Miles

An organism’s phylogeny describes what?

A. acquisition of genes by horizontal gene transfer
B. genomic G+C content
C. chemical composition (percentage of C, N, P, etc.)
D. codon usage compared to other organisms
E. genetic relatedness to other species

E. genetic relatedness to other species

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A(n) _____ is a group of organisms that all share a common ancestor, not shared with any other organism outside of its group.

clade

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Which of the following does not represent a mechanism of horizontal gene transfer among prokaryotes?

A. acquisition of transposable elements
B. transduction
C. transformation
D. conjugal transfer of plasmid DNA
E. binary fission

E. binary fission

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Which of the following conditions would most strongly favor adaptive evolution in bacteria?

A. continuous exposure to antibiotics
B. growth in a nutrient-rich broth
C. growth at moderate temperatures and pH
D. nonobligatory commensal relationships
E. absence of predators or viruses

A. continuous exposure to antibiotics

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Which of the following traits of bacterial cells differ significantly from the other domains of life?

A. nature of genetic code
B. phospholipids in membrane
C. peptidoglycan in cell envelope
D. type of RNA polymerase
E. translation elongation factors
F. DNA as genetic material

C. peptidoglycan in cell envelope
D. type of RNA polymerase
E. translation elongation factors

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What takes place inside of cyanobacterial carboxysomes?

A. buoyancy regulation
B. Krebs cycle
C. nitrogen fixation
D. carbon fixation
E. light-reactions of photosynthesis

D. carbon fixation

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The two major genera of Gram-positive bacteria include the _______________ , which contains the endospore-forming genera (e.g., Bacillus and Clostridium), and the _______________, which contains some filamentous forms (e.g., Streptomyces) that produce exospores.

A. low GC Actinobacteria ; high GC Firmicutes
B. high GC Actinobacteria ; low GC Firmicutes
C. high GC Firmicutes ; low GC Actinobacteria
D. low GC Firmicutes ; high GC Actinobacteria

D. low GC Firmicutes ; high GC Actinobacteria

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Nitrosomas spp. are betaproteobacteria which mediate which important step in the nitrogen cycle?

A. ammonia oxidation
B. ammonification
C. nitrate reduction
D. denitrification
E. nitrite oxidation

A. ammonia oxidation

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The cyanobacteria are thought to have given rise to which eukaryotic organelle?

A. Lysosomes
B. The nucleus
C. Chloroplasts
D. Mitochondria

C. Chloroplasts

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A Gram-positive bacterium with a low GC content may be a(n)

A. Nitrospirae.
B. Actinobacteria.
C. Firmicute.
D. Proteobacteria.

C. Firmicute.

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An example of a Gram-positive, anaerobic, spore-forming microbe is

A. Anabaena.
B. Salmonella.
C. Clostridium.
D. Lactobacillus.

C. Clostridium.

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The closest relatives of mitochondria are found in which bacteria class?

A. Gammaproteobacteria
B. Betaproteobacteria
C. Deltaproteobacteria
D. Alphaproteobacteria

D. Alphaproteobacteria

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Bacteria used in wastewater treatment include those that can convert ammonia and nitrite to nitrate, decreasing the reduced nitrogen content of the sewage. These bacteria, such as Nitrosomonas spp., often belong in

A. Deltaproteobacteria.
B. Gammaproteobacteria.
C. Alphaproteobacteria.
D. Betaproteobacteria.

D. Betaproteobacteria.

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The process of methanogenesis uses a series of specific cofactors to carry each carbon from CO2 (or another substrate) as it becomes progressively reduced by hydrogen. Which of the following is not a cofactor unique to methanogens?

A. coenzyme M (CoM)
B. methanofuran (MFR)
C. tetrahydromethanopterin (H4MPT)
D. cofactor F420 (F420)
E. flavin adenine dinucleotide (FAD+)

E. flavin adenine dinucleotide (FAD+)

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With respect to O2 requirements, most methanogens are which of the following?

A. facultative anaerobes
B. strict aerobes
C. strict anaerobes
D. aerotolerant

C. strict anaerobes

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Methanogenic bacteria are which of the following?

A. strict aerobes that obtain energy through the synthesis of methane
B. strict anaerobes that obtain energy through the consumption of methane
C. strict anaerobes that obtain energy through the synthesis of methane
D. strict aerobes that obtain energy through the consumption of methane

C. strict anaerobes that obtain energy through the synthesis of methane

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Which of the following is true of all archaeans discovered to date?

A. They are unable to synthesize proteins.
B. None of them are human pathogens.
C. They are extremophiles.
D. They are more closely related to bacteria than to eukaryotes.

B. None of them are human pathogens.

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Which of the following produces mushroom fruiting bodies?

A. Basidiomycota
B. Zygomycota
C. Ascomycota
D. Chytridiomycota

A. Basidiomycota

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One reason why fungi cannot perform phagocytosis of food particles is that they

A. do not encounter food particles in their environments.
B. do not need to, because they are photosynthetic.
C. are surrounded by a stiff cell wall.
D. lack necessary cytoskeletal components such as actin.

C. are surrounded by a stiff cell wall.

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Which of the following structures is most likely to be a component of both chytrid zoospores and motile animal cells?

A. Flagella
B. Cilia
C. Pseudopods
D. Frustule

A. Flagella

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Which of the following characteristics are typical of fungi?

A. Mycelium
B. Mixotroph
C. Chloroplasts
D. Cell wall
E. Multicellular
F. Unicellular

A. Mycelium
D. Cell wall
E. Multicellular
F. Unicellular

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Methanogens usually require

A. acidic conditions.
B. methane as a substrate.
C. association with bacterial species.
D. high temperatures.

C. association with bacterial species.

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Life on Earth relies on the production, consumption, and recycling of nutrients. The position that an organism occupies within a food web is referred to as its _____.

trophic level

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What are three types of assimilatory processes?

Photosynthesis
Chemoautotrophy
Nitrogen fixation

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What are three types of dissimilatory processes?

Decomposition Nitrification Aerobic respiration of organic compounds

Which of the following represent prokaryotic primary producers? A. moss B. seaweed C. viruses D. protists E. lithoautotrophs F. fungi G. cyanobacteria

E. lithoautotrophs G. cyanobacteria

What is the order of the food web starting from primary producer?

Primary producer Grazers Primary predator Secondary predator Decomposers

Which of the following symbionts may be found in lichens? A. chemoautotroph B. cyanobacterium C. zooxanthella D. alga E. moss F. fungus

B. cyanobacterium D. alga F. fungus

Fungi that invade plant cells in their roots but do establish a mutualistic relationship are A. endomycorrhizae. B. ectomycorrhizae. C. opportunistic pathogens. D. generalists in terms of their mutualistic relationships.

A. endomycorrhizae.

Soil food webs differ from marine food webs in that A. oxygen is present throughout. B. the role of bacteria is greater than in all trophic levels. C. decomposition is much less important. D. primary production is done mostly by plants.

D. primary production is done mostly by plants.

Suppose various legume plant parts are rubbed with a protein gel. Which plant part is most likely to test positive for nitrogenase? A. Roots B. Leaves C. Stems D. Flowers

A. Roots

Which of the following does NOT contribute to eutrophication? A. Antibiotic runoff B. Excessive nitrogen inputs C. Organic pollutants D. Algal blooms

A. Antibiotic runoff

An organism classified as a barophile is most likely to be found in which habitat? A. Euphotic zone B. Benthic zone C. Epilimnion D. Aerated horizon

B. Benthic zone

How do viruses contribute in the food web?

Decompose bacteria

Biochemical oxygen demand (BOD) is controlled by the concentration of A. multicellular organisms. B. benthic microorganisms. C. heterotrophic microorganisms. D. autotrophic microorganisms.

C. heterotrophic microorganisms.

Syntrophy means A. coupled metabolic pathways in one organism to achieve negative ΔG. B. two organisms eating at the same trophic level. C. using two metabolic pathways simultaneously. D. multiple organisms needed to complete a metabolic pathway with negative ΔG.

D. multiple organisms needed to complete a metabolic pathway with negative ΔG.

Lichens are an example of a mutualism between an alga and a(n) A. animal. B. bacterium. C. fungus. D. plant.

C. fungus.

The major primary producers in terrestrial ecosystems are A. fungi. B. cyanobacteria. C. earthworms. D. land plants.

D. land plants.

A single-celled eukaryote feeds on cyanobacteria (photoautotrophs). The cyanobacteria are considered A. grazers. B. decomposers. C. predators. D. primary producers.

D. primary producers.

An organism fixes nitrogen for the production of amino acids. This is an example of A. assimilation. B. habitat. C. dissimilation. D. predation.

A. assimilation.

Despite the fact that the Earth's crust contains approximately 3,000 times more carbon than the oceans, the oceans are a more important carbon reservoir for most living things. Why is this? A. The carbon in crustal rock cannot be fixed by living organisms. B. The oceans serve as a carbon source but not a carbon sink. C. Carbon cycles quickly between crustal rock and living things. D. Carbon cycles quickly between the oceans and living things.

D. Carbon cycles quickly between the oceans and living things.

What is the ranking of nitrogenous compounds from least oxidized to most oxidized?

NH3 N2 NO2- NO3-

What are the types of carbon reservoirs from smallest amount to largest amount of carbon?

Atmosphere Fossil fuel Ocean Earth's crust

Which reservoir cycles carbon least rapidly? Middle? Most?

Earth's crust Oceans Atmosphere

What are some factors of aerobic carbon cycling?

Supports higher rates of biomass production Occurs in the photic zone of the ocean Includes photosynthetic fixation of CO2

What are some factors of anaerobic carbon cycling?

Includes fermentation Favors incomplete breakdown of organic material Includes respiration that uses nitrate, Fe3+, and sulfate as electron acceptors

What process takes CO2+H2O and converts it to CH2O?

Photosynthesis

What process takes CH2O and converts it to CO2+H2O?

Aerobic respiration

What process takes CH2O and converts it to alcohols and acids (H2+CO2)?

Fermentation

What process takes alcohols and acids (H2+CO2) and converts them to CH2O?

Anaerobic lithotrophy

______ is a fully reduced form of carbon that accumulates deep underground due to limiting ______.

Methane O2

Which of the following statements is true about the relationship between the concentration of organic compounds in a body of water and its biochemical oxygen demand (BOD)? A. As the concentration of organic compounds decreases, the BOD increases. B. The concentration of organic compounds does not affect the BOD. C. As the concentration of organic compounds increases, the BOD decreases. D. As the concentration of organic compounds increases, so does the BOD.

D. As the concentration of organic compounds increases, so does the BOD.

Which of the following is the most direct cause of a rise in biochemical oxygen demand (BOD) in bodies of water? A. respiration by heterotrophs B. chemosynthesis by lithotrophs C. methanogenesis by methanogens D. photosynthesis by cyanobacteria

A. respiration by heterotrophs

The hydrologic and carbon cycles interact. Organic carbon-containing compounds in water act as fuel for __________ by aquatic organisms. This process uses __________ and if the process occurs at too great a rate, __________ dead zones occur in the body of water. A. photosynthesis, carbon dioxide, oxygenated B. respiration, oxygen, hypoxic C. respiration, carbon dioxide, oxygenated D. photosynthesis, oxygen, hypoxic

B. respiration, oxygen, hypoxic

What are the three steps in the "nitrogen triangle"? Place them in the order needed starting from N2.

Nitrogen fixation Aerobic nitrification Anaerobic denitrification

Which of the following processes of the nitrogen cycle is an aerobic process? A. nitrogen fixation B. nitrification C. anammox reaction D. denitrification

B. nitrification

Which of the following nitrogen cycle processes returns N2 to the atmosphere? A. denitrification B. nitrogen fixation C. anammox reaction D. nitrification

A. denitrification C. anammox reaction

Which of the following is the most oxidized form of carbon? A. Methane (CH4) B. Methanol (CH3OH) C. Formic acid (HCOOH) D. Carbon dioxide (CO2)

D. Carbon dioxide (CO2)

In a wastewater treatment plant, microbes are used primarily during __________ treatment. A. secondary B. quaternary C. primary D. tertiary

A. secondary

The primary source and sink of nitrogen is A. the ocean. B. the atmosphere. C. forests. D. soil.

B. the atmosphere.

Nitrogen is often a limiting nutrient for plant growth because A. human activities have reduced the nitrogen concentration in the environment. B. plants cannot use the most abundant form of nitrogen (N2). C. it is a small percentage of the atmosphere. D. nitrogen is not transported into plant cells efficiently.

B. plants cannot use the most abundant form of nitrogen (N2).

Cellular nitrogen fixation A. can occur in both prokaryotes and eukaryotes. B. leads to the oxidation of nitrogen. C. occurs in the absence of an enzyme. D. requires a lot of energy.

D. requires a lot of energy.

Which of the following is a true statement about dissimilatory nitrate reduction? A. It occurs mainly in the presence of oxygen gas (O2). B. Nitrate acts as an electron donor. C. It is not an important pathway in the biogeochemical nitrogen cycle. D. It can lead to the production of N2 or ammonia.

D. It can lead to the production of N2 or ammonia.

Which of the following is the most oxidized form of nitrogen? A. NO B. NH3 C. NO2– D. NO3–

D. NO3–

Define clade:

group of species that once shared a common ancestor

Define taxonomy:

description of life forms and their classification into groups

What is the order of taxonomy from largest to smallest?

class-order-family-genus-species

Define horizontal gene transfer:

transfer of one or more genes between unrelated species

Define vertical gene transfer:

linked to DNA replication and cell duration WHOLE GENOME copied and passed to offspring

Define symbiosis:

association between two or more species

Define mutualism:

type of symbiosis both partner benefit

Define endosymbiosis:

type of symbiosis one partner lives inside the body of another

Define syntrophy:

type of symbiosis 2 or more partners depend on each other for the completion of their metabolism

Define co-evolution:

endosymbiotic relationship where both partners evolve together involves reductive evolution of the endosymbiont

Define ecosystem:

habitat and the organisms living in it

Define assimilation:

part of ecosystem primary producers -CO2 fixation, N2 fixation, photosynthesis

Define dissimilation:

part of ecosystem consumers and decomposers -respiration, fermentation, heterotrophy

What are the 4 ocean layers?

Neuston Euphotic zone Aphotic zone Benthos

What is the neuston?

top ocean layer interface between water and air

What is the euphotic layer?

the "true" layer of the ocean few meters below surface, light CAN penetrate

What is the aphotic layer?

second to bottom layer of the ocean deeper layers of the ocean were light CANNOT penetrate

What is the benthos?

bottom layer of the ocean ocean floor and sediment below

What are the 2 soil layers?

Top Bottom

What is unique about the top layer of soil?

aerobic layer

What is unique about the bottom layer of soil?

anoxic layer

Define bacteroid:

rhizobium sheds its cell wall when inside the root cells of leguminous plants

Define reservoir:

part of the biosphere with significant amounts of an element -C, N, S

Define a sink:

part of a reservoir where the element returns to

Define a source:

part of a reservoir for the element for organisms that use it

Define biochemical O2 demand (BOD):

need for oxygen in an ecosystem increases in a water body when waterbody gets eutrophied

What type of water body has a high BOD?

eutrophic

What type of water body has a low BOD?

oligotrophic

What are the 3 mechanisms of divergence from common ancestors?

Random mutation Natural selection (gene gain) Reductive evolution (unwanted traits lost)

Which gene is most commonly used in phylogenetic trees? Why?

SSU rRNA universal and sequence of nucleotides differs between species

What are the 3 domains of life?

Archaea (prokaryote) Bacteria (prokaryote) Eukaryotes

What's the difference between prokaryotes and eukaryotes?

prokaryotes do not have a true nucleus, eukaryotes do have one

What do all domains of life share?

DNA Similar cell architecture (cytoplasm surrounded by cell membrane) Central dogma

Define the central dogma of microbiology:

genes --> transcription --> RNA --> translation --> proteins

What types of metabolism are NOT present in eukaryotes?

N2 fixation Lithotrophy Methanogenesis

What types of metabolism are common to ALL domains of life?

Respiration Fermentation

What type of metabolism are unique to archaea? Why?

Methanogenesis --> archaea are strict anaerobes --> CO2 needed for carbons --> methanofuran needed as electron carrier --> product id CH4 (methane, most reduced form of C) --> occurs in anoxic environments (no oxygen)

What is an example of an anoxic environment?

landfills. waste treatment plants, etc

What domain of life has no known pathogens?

archaea

What do bacteria and archaea have in common?

circular genome no true nucleus and no nuclear membrane

What passes in horizontal gene transfer?

a piece of DNA with 1 or more genes

Between what does horizontal gene transfer occur?

unrelated species

How does horizontal gene transfer occur?

with a plasmid (virus related) conjugation --> transformation --> transduction

Why does horizontal gene transfer occur?

increases chances of survival under the current conditions meets conditional needs

What passes in vertical gene trasnfer?

the full genome

Between what does vertical gene trasnfer occur?

mother cell and an offspring

How does vertical gene transfer occur?

1 - replicate DNA 2 - cell divides

Where was the endosymbiotic origin of mitochondria?

alpha-proteobacteria

What genes are encoded on the mitochondria that are important for the survival of the host?

respiration

Where was the endosymbiotic origin of the chloroplast?

cyanobacteria

What genes are encoded on the chloroplast that are important for the survival of the host?

CO2 fixation (CO2 --> sugar) photosynthesis

What are some characteristics that diversify cyanobacteria?

photosynthesis is oxygenic fixes CO2 via Calvin Cycle carboxysomes marine types can fix N2 using N2ase heterocysts

What are the three subclasses of bacterium?

cyanobacteria gram positive gram negative

What are the two subclasses of gram positive bacteria?

firmicutes actinobacteria

What is an example of actinobacteria?

mycobacterium

What are the two subclasses of firmicutes?

spore former non-spore former

What types of bacteria are spore formers?

bacillus clostridium

What types of bacteria are non-spore formers?

staphylococcus streptococcus

What is an example of gram negatives bacterium?

proteobacteria

What are the 4 subclasses of proteobacteria?

alpha-proteobacteria beta-proteobacteria gamma -proteobacteria delta-proteobacteria

What types of bacteria are alpha-proteobacteria?

rhizobium N2 fixation legume plants

What types of bacteria are beta-proteobacteria?

nitrosomonas nitrification

What types of bacteria are gamma-proteobacteria?

E-coli dentrification

What types of bacteria are delta-proteobacteria?

Sulfate-reducing bacteria

Where can methanogens be found?

termite gut rumen waste water treatment

Where are halophilic archaea found? Why?

salted foods solar salterns hypersaltern lakes NOT THE OCEAN/SEA requires high concentration of salt

What are 3 traits common to all filamentous funhi?

1 - have chitin in cell wall 2- absorptive nutrition 3- myceluin / hyphae

What is a trait common in all unicellular fungi like yeast (non-filamentous)?

budding reproduction

What are the 4 fungal phyla? What are examples of each?

chytridis myata --> anaerobic rumen fungi zygo --> glomus endomyeo rrhizae aseo --> morelol truffles basidis --> mushrooms

Define assimilation

inorganic elements become a form that we can assimilate inorganic to organic

Define dissimilation

organic forms of an element breaks down to inorganic forms of element organic to inoganic

What are some examples of assimilation?

CO2 fixation photosynthesis N2 fixation

What are some examples of dissimulation?

respiration fermentation

At what trophic state does assimilation occur?

primary producers

At what trophic state does dissimulation occur?

consumers and decomposers

What organisms have a mutualistic relationship with lichens?

algae and/or cyanobacteria bacteria

What is the function of the mutualistic relationships with lichens and algae/cyanobacteria/fungi?

photosynthesis and CO2 fixation provides C to the partner (algae/cyanobacteria) protect the system (fungi)

What organisms have a mutualistic relationship with the termite gut microbes?

termite and other microbes in the gut bacteria and methanogen

What is the function of the mutualistic relationship between the termite gut and the termite+community in the gut?

provide wood (termite) break down wood (community) endosymiotic relationship

What is the function of the mutualistic relationship between the termite gut and bacteria+methanogens?

break down wood into simple sugars + CO2 + H2 (bacteria) help keep H2 concentration down (methanogens) syntrophic relationship

What organisms have a mutualistic relationship with mycorrhiza?

plant roots and fungi

What is the function of the mutualistic relationship between mycorrhiza and plantroots+fungi?

photosynthesis and CO2 fixation provide C to fungus (plant roots) ECTOMYCORRHIZAE absorb nutrient from meter away (fungi) ENDOSYMBIOSIS penetrates inside root cells, endomycorrhizae (fungi) ZYGOMYCOTA

What organisms have a mutualistic relationship with leguminous plants?

plant roots and rhizobium

What is the function of the mutualistic relationship between leguminous plants and plant roots+rhizobium?

photosynthesis and CO2 fixation to provide fixed C to rhizobium (plant roots) bacterois wall fixes N2 and creates Nh# (rhizobium) endosymbiosis relationship

What organisms have a mutualistic relationship with the rumen microbes?

cow + community in gut bacteria/fungi + methanogen

What is the function of the mutualistic relationship between the rumen microbes and the cow+community / bacteria+fungi+methanogen?

eat plants (cow) digest plants (community ABOVE ARE ENDOSYMBIOTIC break down complex plant fibers (bacteria+fungi) help keep H2 concentration down (methanogen) ABOVE ARE SYNTROPHY

What are the primary producers in the ocean?

algae and cyanobacteria

What are the primary producers in the soil?

green plants

What are the consumers in the ocean?

bacteria and archaea

What are the consumers in the soil?

protists and fungi

What are the decomposers of the ocean?

viruses

What are the decomposers of the ocean?

viruses

What are the decomposers of the soil?

bacteria and fungi

In which stage of waste water treatment are microbes involved?

secondary treatment

Which microbes are involved in wastewater treatment? What do they do?

aerobic heterotrophs --> aerobic respiration to convert the C load to an organic form like CO2 methanogens --> help keep the H2 concentration down

How do we inoculate wastewater treatment bacteria and why?

pump O2 to keep aerobes happy in the form of flocs

Where is the LARGEST reservoir of carbon?

carbonate rock / earth crust

Where is the FASTEST reservoir to recycle carbon?

atmosphere

Where is the LARGEST reservoir for nitrogen?

atmosphere

Eutrophic (true growth) water bodies have ____ carbon content and _____ biological O2 demand.

high, high

Oligotrophic (few) water bodies have _____ carbon content and _____ biological O2 demand.

low, low

What is the most negative oxidation state of carbon?

CH4

What is the most negative oxidation state of nitrogen?

NH3

What is the most negative oxidation state of sulfur?

H2S

What is the most neutral oxidation state of carbon?

organic C like sugar

What is the most neutral oxidation state of carbon?

What is the most neutral oxidation state of sulfur?

elemental S

What is the most positive oxidation state of carbon?

CO2

What is the most positive oxidation state of nitrogen?

NO3 (nitrate)

What is the most positive oxidation state of sulfur?

SO4 (sulfate)

Most negative oxidation state means what?

lots of electrons most REDUCED can only be OXIDIZED can only DONATE electrons can only be an electron DONOR

Most positive oxidation state means what?

most OXIDIZED can only be REDUCED can only ACCEPT electrons can only be an electron ACCEPTOR

Which element has the MOST oxidized state?

nitrogen

Exam 4 Flashcards

(177 cards)