Brainscape_Metabolism_Flashcards
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What is the primary function of macrophages?
Clearance of microbes, apoptotic cells, and foreign particles.
What are the two major types of macrophage polarization?
M1 (pro-inflammatory) and M2 (anti-inflammatory).
What are the key metabolic features of M0 (naïve) macrophages?
Low catabolic/anabolic activity, rely on OXPHOS for ATP.
What is the main metabolic pathway in M1 macrophages?
Increased glucose uptake and glycolysis; broken TCA cycle; no OXPHOS.
What metabolic products are generated by M1 macrophages?
NADPH (via PPP), nitric oxide (via iNOS), and fatty acids.
What is the main metabolic pathway in M2 macrophages?
Active TCA cycle, β-oxidation, and glutamine metabolism; rely on OXPHOS.
How does M2 macrophage glycolysis compare to M1?
Decreased glycolysis and PPP compared to M1.
What is the role of IRG1 and itaconate in M1 macrophages?
IRG1 upregulation leads to itaconate production, which inhibits succinate dehydrogenase.
Why is succinate accumulation important in M1 macrophages?
It drives production of IL-1β, fueling inflammation.
What are the three general types of bacterial metabolism?
Heterotrophic, autotrophic, and phototrophic.
What are heterotrophic bacteria?
Bacteria that require organic molecules for carbon and energy.
How do obligate aerobes differ from facultative anaerobes?
Obligate aerobes require oxygen; facultative anaerobes can use or live without it.
What is the function of the glyoxylate pathway in bacteria?
Allows growth on 2-carbon compounds like acetate; bypasses CO2-producing steps of TCA.
What is the role of phosphofructokinase in bacterial glycolysis?
It catalyzes the conversion of fructose-6-P to fructose-1,6-BP.
What sugar metabolism pathway includes tagatose intermediates?
Galactose metabolism.
What is the fate of pyruvate in bacteria?
Depends on energy needs and enzymatic capacity (can enter TCA, fermentation, etc).
What are denitrifying bacteria capable of?
Reducing nitrate (NO3-) to nitrogen gas (N2) under anaerobic conditions.
What is Salmonella enterica?
A facultative intracellular pathogen and facultative anaerobe.
How does Salmonella enter the host?
Through contaminated food/water via the intestinal epithelium.
What carbon sources can Salmonella use?
Glucose, glycerol, acetate, fatty acids, lactate, succinate, etc.
How does Salmonella exploit host metabolism?
By using host-derived metabolites like succinate, nitrate, tetrathionate.
What metabolic adaptation does intracellular Salmonella undergo?
Increased lipid import and β-oxidation; activates glyoxylate pathway.
How does itaconate affect Salmonella?
It inhibits isocitrate lyase, limiting bacterial survival.
