[PSM] Bacteriology Flash Review - Physio

Proton motive force

Force created by ETC to power ATP synthesis

Cyanobacteria

Lone bacterial group that can do oxygenic photosynthesis

PS I

What photosystem enables cyanobacteria to do anoxygenic photosynthesis?

Byproduct: Oxygen
Electron Donor (Reducing Power): Water

In oxygenic photosynthesis, what is the byproduct and what is the electron donor?

Chlorophylls contain Mg in the center of the ring, whereas cytochromes have Fe

Describe the key difference between chlorophylls and cytochromes

Chlorophyll a

Principal chlorophyll of oxygenic phototrophs

680 nm, 430 nm

Chlorophyll a has strong absorbance at what wavelengths?

PSI or P700 - Iron Sulfur (FeS) reaction center
PSII or P680 - Quinone reaction center

Match the Photosystems and Reaction centers

Plastoquinone to Cytochrome b6f

In oxygenic photosynthesis, the transfer of electrons from these two electron carriers causes the creation of PMF which will be used to generate ATP (non-cyclic)

Ferredoxin-NADP oxidoreductase

Once this electron carrier receives the electron in oxygenic photosynthesis, it can result to the creation of NADP and NADPH

Cyclic, Non-cyclic

What kind/s of electron flow is expected in oxygenic photosynthesis?

Byproduct: Diverse (e.g. SO4 2-)
Electron Donor (Reducing Power): Diverse (e.g. H2S), Except H2O

In anoxygenic photosynthesis, what is the byproduct and what is the electron donor?

Anoxygenic Photosynthesis

The first phototrophic organisms would have done what kind of photosynthesis?

Bchl a and b

Bacteriochlorophyll: Purple bacteria

Bchl c, d, e

Bacteriochlorophyll: Green sulfur bacteria

Bchl c

Bacteriochlorophyll: Acidobacteria

Bchl c_s

Bacteriochlorophyll: Green nonsulfur bacteria

Bchl g

Bacteriochlorophyll: Heliobacter

Q type RC
Cyclic electron flow
Reverse electron flow

For purple and green nonsulfur bacteria, what kind of RC do they respond to? What electron flow generates PMF? What do they do if they need to synthesize NADH?

TRUE

T/F: Phototrophy is unique to Domain Bacteria

FALSE

T/F: Phototrophy is found in both Domain Archaea and Bacteria

TRUE

T/F: Oxygenic phototrophy is unique to cyanobacteria

FALSE

T/F: Anoxygenic phototrophy is unique to cyanobacteria

Nitrogen Fixation

Formation of ammonia from nitrogen gas

Nitrogenase

What enzyme converts nitrogen to ammonia?

Dinitrogenase, Dinitrogenase reductase

Nitrogenase consists of what proteins?

Oxygen gas

What can inhibit nitrogenase activity?

Pyruvate

Electron donor for nitrogenase activity

1 N₂ + 16 ATP → 2 NH₃ + 16 ADP + 16 P_i

General formula for nitrogenase activity

Respiration, Production of O₂ retarding slime layers

What are 2 ways in which obligate aerobes can remove O₂ so that they can do nitrogen fixation?

Heterocyst

Differentiated cell in cyanobacteria that protects the nitrogenase and serves as a site for N₂ fixation?

Leghemoglobin

Iron-containing, O₂-binding protein in root nodules that serves as an oxygen buffer

Oxygen

Final electron acceptor for aerobic respiration

Other electron acceptors other than oxygen

Final electron acceptor for anaerobic respiration

TRUE

T/F: Both aerobic and anaerobic respiration can be found in chemoorganotrophs and chemolithotrophs

FALSE

T/F: Both aerobic and anaerobic respiration can be found in chemoorganotrophs, but only anaerobic respiration can be found in chemolithotrophs

Oxidative phosphorylation

ATP formation by ATP synthase using PMF generated by respiratory electron flow

Hydrogen oxidation
Sulfur compound oxidation
Iron oxidation
Nitrification
Anammox

5 respiratory processes according to electron donor that uses oxygen as final electron acceptor (SHINA)

Donor - H₂

Acceptor - O₂

Electron donor and acceptor: Hydrogen oxidation

Hydrogen Oxidation

What kind of process occurred here: H2 + ½ O2 ➡ H2O

Donor - H₂S, S⁰, S₂O₃ ^2-, SO₃ ^2-

Acceptor - O₂

Electron donor and acceptor: Sulfur compound oxidation

Sulfate

In sulfur compound oxidation, what is the expected product?

Fe²⁺ (Ferrous iron) → Fe³⁺ (Ferric iron) → Insoluble ferric hydroxide and other iron precipitates

Reaction: Iron Oxidation

Donor: Fe2+

Acceptor: O2, Fe3+

Electron donor and acceptor: Iron oxidation

Nitrosomonas

Bacteria responsible for the oxidation of ammonia to nitrite

Nitrobacter

Bacteria responsible for the oxidation of nitrite to nitrate

Nitrification

Aerobic oxidation of reduced inorganic nitrogen compounds (Ammonia/NH3 ) and nitrite (NO2 -)

Obligate anaerobic bacteria

What kind of bacteria can do anammox?

Anaerobic ammonia oxidation

Reaction wherein NH3 is oxidized to N2 using NO2 as the electron acceptor

Anammoxosome

Unit membrane-enclosed structure that serves as a site for oxidation of NH3 to N2 in obligate anaerobic bacteria

Denitrification

Biological production of gaseous N compounds

Pseudomonas stutzeri

Bacteria that can do denitrification

Nitrate → Nitrite → Nitric Oxide → Nitrous Oxide → Dinitrogen

Denitrification outline

Disproportionation

Method of thiosulfate reduction that is used for bioremediation

Assimilatory

Type of sulfate and sulfur reduction wherein sulfur is produced in the process and a part of the biomass

Dissimilatory

Type of sulfate and sulfur reduction wherein sulfide is produced but excreted, leading to higher hydrogen sulfide production

Thiosulfate + H2O → H2S + SO4

Disproportionation reaction

Donor: Substrate

Acceptor: Substrate

Electron Donor and Acceptor: Fermentation

Phosphate bond, Molecule of CoA

For an organic compound to be energy rich, what must it contain?

Substrate Level Phosphorylation

Process wherein an energy-rich bond of a substrate is hydrolyzed to directly drive the formation of ATP

SLP - 2 ATP

OP - 38 ATP

What is the ATP yield for Substrate Level and Oxidative Phosphorylation?

Fermentation-respiration switch

refers to a cell's ability to shift between using fermentation and aerobic respiration based on oxygen availability

Homofermentative

Type of fermentation with a single fermentation product

Heterofermentative

Type of fermentation with mixed fermentation products, occirs more often