Advanced Microbiology – Final Exam
Questions and Answers 2025/2026 Edition |
Verified Practice Q&A| HIGHLY GRADED A+
Reduction - CORRECT ANSWERS--reduce precursors with reducing power (NADH) to
make new cellular material
Chemoorganoheterotrophic - CORRECT ANSWERS--Energy source: chemical
e source: organic
C source: organic
chemolithoheterotroph - CORRECT ANSWERS--carbon source: organic carbon
energy source: chemicals
electron source: inorganic e- donor
Chemolithoautotrophs - CORRECT ANSWERS--energy from inorganic compounds;
carbon from CO2, e donor is inorganic
Photoheterotrophs - CORRECT ANSWERS--Energy from sunlight, carbon from organic
compounds
Photoautotrophs - CORRECT ANSWERS--An organism that harnesses light energy to
drive the synthesis of organic compounds from carbon dioxide.
NADH - CORRECT ANSWERS--An energy-carrying coenzyme produced by glycolysis
and the Krebs cycle. NADH carries energy to the electron transport chain, where it is
stored in ATP.
Nicotinamide adenine dinucleotide
CO2 fixation requirements (chemolithotroph) - CORRECT ANSWERS--- Need ATP
(from oxidation of inorganic e donor)
- Reducing power (CO2 reduced) (NADH) = reverse e transport reaction
H2 oxidation aerobic - CORRECT ANSWERS--1. Hydrogenase: H2 into H+ E
2. e through the membrane: e to O2 (proton motive force)
3. NADH production: Cytoplasmic dehydrogenase (NAD+ to NADH)
Calvin cycle
,H2 oxidation anaerobic - CORRECT ANSWERS--Other e acceptor (small carbon
source)
Sulphur oxidation - CORRECT ANSWERS--Acceptors: H2S, S0, S2O3-2
Often leads to: H2S + O2 = SO4-2 + H+
In steps: S0 = SO3-2 = SO4-2
reverse electron flow - CORRECT ANSWERS--ATP is used to generate reducing power
by forcing electrons or hydrogen atoms back through an electron transport chain and
reduce NAD(P)+ to NAD(P)H. this is the reverse of chemiosmosis which usually
converts reducing power in the form of NADH into ATP. THis proves that ATP and a
protein gradient are interconvertible
Iron Oxidation - CORRECT ANSWERS--the aerobic oxidation of ferrous iron to ferric
iron, which supports growth of the chemolithotrophic "Iron bacteria"
Fe+2 = Fe+3
Aerobic (Thiobaccilus ferroxidans, Leptospirillum ferroxidans)
Rusticyanin: e acceptor of Fe+2
N-oxidation - CORRECT ANSWERS--e-donors: NH3, NO2-
1. Nitrosofyers: NH3 = N02-
2. Nitrobacter: N02- = NO3-
Step 1 of N-oxidation - CORRECT ANSWERS--1. Ammonium monoxygenase
(cytoplasm)
NH3 = NH2OH
2. Hydroxylamine oxidoreductase (periplasm)
NH2OH = N02-
Liberates e
Step 2 of N-oxidation - CORRECT ANSWERS--3. Nitrate oxidoreductase
NO2- = NO3-
e: proton motive force
,annamox reaction - CORRECT ANSWERS--Anoxic environment
NH4 + NO2 = N2 + H2O
waste water treatment
1. Nitrite reductase (N02- = NO)
2. Hydrazine synthase (NO + NH4+ = N2H4)
3. Hydrazine dehydrogenase (N2H4 = N2 + e)
Anammoxome - CORRECT ANSWERS--Organelle for annamox
Toxic product (hydrazine) stored here
Lipids to avoid diffusion out
Photoautotrophs organisms - CORRECT ANSWERS--Algae, cyanobacteria,
green/purple sulphur bacteria
Photoheterotrophs organisms - CORRECT ANSWERS--Green/purple non-sulphur
bacteria, heliobacteria
Photosynthesis light reaction - CORRECT ANSWERS--use light for ATP making
Photosynthesis dark reaction - CORRECT ANSWERS--CO2 is fixed in the Calvin cycle,
and carbohydrates are synthesized.
Chlorophyll - CORRECT ANSWERS--Porphyrin ring structure with Mg at the center
different wavelengths absorptions:
- more efficient use of the light
- less competition
Chlorophyll (oxygenic photosynthesis) - CORRECT ANSWERS--a (absorbs blue/red
light) (reflect green light)
Chlorophyll (anoxygenic photosynthesis) - CORRECT ANSWERS--bacteriochlorophyls
More absorption range
Chlorophyll storage prokaryotes - CORRECT ANSWERS--1. invagination of
cytoplasmatic membrane
2. Cytoplasmatic membrane (Heliomembrane)
3. Membrane-enclosed (Cyanobacteria)
Working principle: associated with protein = complexes
Small part: reaction centers
, Surrounded by antenna chlrophylls (harvest light, funnel it to RC)
Carotenoids - CORRECT ANSWERS--An accessory pigment, either yellow or orange,
in the chloroplasts of plants. By absorbing wavelengths of light that chlorophyll cannot,
carotenoids broaden the spectrum of colors that can drive photosynthesis.
Photoprotective role
phycobilins - CORRECT ANSWERS--Light-absorbing antenna for photosynthesis
Absorb at green-orange region
Purple sulphur bacteria (anoxygenic bacteria) - CORRECT ANSWERS--1. ATP
production
2. NADPH (reverse e flow)
Location: invagination of plasma membrane
Heliobacteria + green sulphur bacteria (anoxygenic bacteria) - CORRECT ANSWERS--
Allochromatium and Thiocapsa
Illuminated anoxic zones of aquatic bodies
H2S accumulates = purple bacteria accumulation
Ferrodoxin - CORRECT ANSWERS--electron carrier that become reduced with FeS
oxygenic photosynthesis - CORRECT ANSWERS--Cyanobacteria
ATP (non-cyclic photophorylation + proton motive force)
NADPH generation: Through membrane as a "z"
Autotrophic CO2 fixation - CORRECT ANSWERS--Dark reactions
CO2 = cell material
Calvin cycle: Rubisco + phosphoribulokinase
Rubisco - CORRECT ANSWERS--1. Rubisco
Creates an unstable intermediate that hydrolyses to PGA
2. During cycle
ATP usage for the next enzymes
Questions and Answers 2025/2026 Edition |
Verified Practice Q&A| HIGHLY GRADED A+
Reduction - CORRECT ANSWERS--reduce precursors with reducing power (NADH) to
make new cellular material
Chemoorganoheterotrophic - CORRECT ANSWERS--Energy source: chemical
e source: organic
C source: organic
chemolithoheterotroph - CORRECT ANSWERS--carbon source: organic carbon
energy source: chemicals
electron source: inorganic e- donor
Chemolithoautotrophs - CORRECT ANSWERS--energy from inorganic compounds;
carbon from CO2, e donor is inorganic
Photoheterotrophs - CORRECT ANSWERS--Energy from sunlight, carbon from organic
compounds
Photoautotrophs - CORRECT ANSWERS--An organism that harnesses light energy to
drive the synthesis of organic compounds from carbon dioxide.
NADH - CORRECT ANSWERS--An energy-carrying coenzyme produced by glycolysis
and the Krebs cycle. NADH carries energy to the electron transport chain, where it is
stored in ATP.
Nicotinamide adenine dinucleotide
CO2 fixation requirements (chemolithotroph) - CORRECT ANSWERS--- Need ATP
(from oxidation of inorganic e donor)
- Reducing power (CO2 reduced) (NADH) = reverse e transport reaction
H2 oxidation aerobic - CORRECT ANSWERS--1. Hydrogenase: H2 into H+ E
2. e through the membrane: e to O2 (proton motive force)
3. NADH production: Cytoplasmic dehydrogenase (NAD+ to NADH)
Calvin cycle
,H2 oxidation anaerobic - CORRECT ANSWERS--Other e acceptor (small carbon
source)
Sulphur oxidation - CORRECT ANSWERS--Acceptors: H2S, S0, S2O3-2
Often leads to: H2S + O2 = SO4-2 + H+
In steps: S0 = SO3-2 = SO4-2
reverse electron flow - CORRECT ANSWERS--ATP is used to generate reducing power
by forcing electrons or hydrogen atoms back through an electron transport chain and
reduce NAD(P)+ to NAD(P)H. this is the reverse of chemiosmosis which usually
converts reducing power in the form of NADH into ATP. THis proves that ATP and a
protein gradient are interconvertible
Iron Oxidation - CORRECT ANSWERS--the aerobic oxidation of ferrous iron to ferric
iron, which supports growth of the chemolithotrophic "Iron bacteria"
Fe+2 = Fe+3
Aerobic (Thiobaccilus ferroxidans, Leptospirillum ferroxidans)
Rusticyanin: e acceptor of Fe+2
N-oxidation - CORRECT ANSWERS--e-donors: NH3, NO2-
1. Nitrosofyers: NH3 = N02-
2. Nitrobacter: N02- = NO3-
Step 1 of N-oxidation - CORRECT ANSWERS--1. Ammonium monoxygenase
(cytoplasm)
NH3 = NH2OH
2. Hydroxylamine oxidoreductase (periplasm)
NH2OH = N02-
Liberates e
Step 2 of N-oxidation - CORRECT ANSWERS--3. Nitrate oxidoreductase
NO2- = NO3-
e: proton motive force
,annamox reaction - CORRECT ANSWERS--Anoxic environment
NH4 + NO2 = N2 + H2O
waste water treatment
1. Nitrite reductase (N02- = NO)
2. Hydrazine synthase (NO + NH4+ = N2H4)
3. Hydrazine dehydrogenase (N2H4 = N2 + e)
Anammoxome - CORRECT ANSWERS--Organelle for annamox
Toxic product (hydrazine) stored here
Lipids to avoid diffusion out
Photoautotrophs organisms - CORRECT ANSWERS--Algae, cyanobacteria,
green/purple sulphur bacteria
Photoheterotrophs organisms - CORRECT ANSWERS--Green/purple non-sulphur
bacteria, heliobacteria
Photosynthesis light reaction - CORRECT ANSWERS--use light for ATP making
Photosynthesis dark reaction - CORRECT ANSWERS--CO2 is fixed in the Calvin cycle,
and carbohydrates are synthesized.
Chlorophyll - CORRECT ANSWERS--Porphyrin ring structure with Mg at the center
different wavelengths absorptions:
- more efficient use of the light
- less competition
Chlorophyll (oxygenic photosynthesis) - CORRECT ANSWERS--a (absorbs blue/red
light) (reflect green light)
Chlorophyll (anoxygenic photosynthesis) - CORRECT ANSWERS--bacteriochlorophyls
More absorption range
Chlorophyll storage prokaryotes - CORRECT ANSWERS--1. invagination of
cytoplasmatic membrane
2. Cytoplasmatic membrane (Heliomembrane)
3. Membrane-enclosed (Cyanobacteria)
Working principle: associated with protein = complexes
Small part: reaction centers
, Surrounded by antenna chlrophylls (harvest light, funnel it to RC)
Carotenoids - CORRECT ANSWERS--An accessory pigment, either yellow or orange,
in the chloroplasts of plants. By absorbing wavelengths of light that chlorophyll cannot,
carotenoids broaden the spectrum of colors that can drive photosynthesis.
Photoprotective role
phycobilins - CORRECT ANSWERS--Light-absorbing antenna for photosynthesis
Absorb at green-orange region
Purple sulphur bacteria (anoxygenic bacteria) - CORRECT ANSWERS--1. ATP
production
2. NADPH (reverse e flow)
Location: invagination of plasma membrane
Heliobacteria + green sulphur bacteria (anoxygenic bacteria) - CORRECT ANSWERS--
Allochromatium and Thiocapsa
Illuminated anoxic zones of aquatic bodies
H2S accumulates = purple bacteria accumulation
Ferrodoxin - CORRECT ANSWERS--electron carrier that become reduced with FeS
oxygenic photosynthesis - CORRECT ANSWERS--Cyanobacteria
ATP (non-cyclic photophorylation + proton motive force)
NADPH generation: Through membrane as a "z"
Autotrophic CO2 fixation - CORRECT ANSWERS--Dark reactions
CO2 = cell material
Calvin cycle: Rubisco + phosphoribulokinase
Rubisco - CORRECT ANSWERS--1. Rubisco
Creates an unstable intermediate that hydrolyses to PGA
2. During cycle
ATP usage for the next enzymes
