Lecture 8 Flashcards
(41 cards)
What are the two parts of a species genome?
Core genome and pan genome
Core genome consists of genes shared by all strains, while pan genome includes core genome plus genes not shared by all strains.
What are chromosomal islands?
Genomic regions that can encode virulence factors and other traits
Examples include pathogenicity islands and pollutant-degradation pathways.
What is a pathogenicity island?
A chromosomal island that encodes virulence factors
Found in pathogenic bacteria like uropathogenic E. coli and Staphylococcus aureus.
What is the significance of gene sampling in microbes?
Microbes constantly sample genes from other organisms in their environment, leading to genomic diversity.
How do some bacteria acquire energy and build up biomass?
By depending on glycolysis and fermentation
They must acquire sugars and amino acids from their host.
What is the Calvin Cycle?
The most widespread pathway for CO2 fixation used by oxygenic phototrophs
Key enzyme is RubisCO, requiring 12 NADPH and 18 ATP to synthesize 1 fructose-6-phosphate.
Define the Reverse Citric Acid Cycle.
Also called reductive TCA cycle; used by green sulfur bacteria to fix CO2
It is more efficient than the Calvin cycle, requiring 24H and 10 ATP to fix 6 CO2.
What is photophosphorylation?
The process of converting sunlight energy into ATP production through PMF
It involves both phototrophs and respiration.
What occurs during oxygenic photosynthesis?
Light reactions occur in specialized photosynthetic membranes
In eukaryotes, this occurs in chloroplasts; in cyanobacteria, it occurs in stacked membranes in the cytoplasm.
What is the role of methanogens?
Strictly anaerobic Archaea that catalyze methanogenesis
They are found in various environments including freshwater sediments and animal guts.
What are nitrifying bacteria responsible for?
Oxidizing ammonia and nitrite aerobically during nitrification
They are widely distributed in soil, water, and wastewater.
What defines fermentations?
Energy conservation depends on substrate-level phosphorylation without external electron acceptors.
Fill in the blank: The key enzyme in the Calvin Cycle is _______.
RubisCO
True or False: The Reverse Citric Acid Cycle requires unique enzymes not found in the regular citric acid cycle.
True
List three types of autotrophic pathways.
- Calvin Cycle
- Reverse Citric Acid Cycle
- Other unique pathways
What is the impact of aerobic oxidation of ferrous iron?
Supports chemolithotrophic ‘iron bacteria’ and drives down pH
Many iron oxidizers are strongly acidophilic.
What is the oxidation state of Nitrogen gas (N2)?
0
What is the main difference between dissimilative and assimilative processes?
Dissimulative processes release energy, while assimilative processes incorporate nitrogen into organic compounds.
What is the metabolic product of Hexose in the presence of Butyric acid?
Butyrate, 2 H2, 2 CO2, H+
Produced by Clostridium butyricum
What does Hexose yield when converted by Clostridium acetobutylicum?
Butanol, acetone, 5 CO2, 4 H2
The reaction has a ΔG of -468 kJ/mol
What are the products of 6 ethanol and 3 acetate in the presence of Clostridium kluyveri?
3 butyrate, caproate, 2 H2, 4 H2O, H+
The reaction has a ΔG of -183 kJ/mol
What is the ΔG value for the conversion of Hexose to 2 ethanol and 2 CO2?
-239 kJ/mol
What are the products of Hexose during lactic acid fermentation?
Lactate, ethanol, CO2, H2
The reaction has a ΔG of -216 kJ/mol
Which phyla can be distinguished based on 16S ribosomal RNA?
80+ phyla
