1.2 Flashcards
Macroelements (required in larger amounts) (2)
C, O, N, H, S, P
components of carbohydrates, lipids, proteins
and nucleic acids
K, Ca, Mg, Fe
exist as cations and play many roles, including
cofactors of enzymes
Trace elements (required in smaller amounts) (2)
Mn, Zn, Co, Mb, Ni, Cu
mainly needed as cofactors of enzymes
Sources of Energy
Phototrophs
Light
Sources of Energy
Chemotrophs (2)
oxidation of organic or
inorganic compounds
Sources of Reducing Equivalents
Need electron donors for (3)
electron transport chain (energy production)
oxidation-reduction rxns (includes energy production)
biosynthesis in autotrophs (from CO2)
Sources of Reducing Equivalents
Lithotrophs
reduced inorganic molecules
Sources of Reducing Equivalents
Organotrophs
organic molecules
Sources of Carbon
Autotrophs
CO2 main/only source
Sources of Carbon
Heterotrophs
reduced, preformed organic molecules
Photolithotrophic autotrophy (3)
light energy
inorganic electron donor
CO2 carbon source
Photoorganotrophic heterotrophy (3)
light energy
organic electron donor
organic carbon source
Chemolithotrophic autotrophy (3)
chemical energy source
inorganic electron donor
CO2 carbon source
Chemoorganotrophic heterotrophy (3)
chemical energy source
(all pathogens) organic electron donor
organic carbon source
N
source amino acids, ammonia
nitrate = ammonia N2
P source
inorganic phosphate (PO43-)
S source (2)
sulfate (SO42-) reduced sulfur (e.g. cysteine)
Growth factors (3)
amino acids
purines and pyrimidines
vitamins (small organic molecules)
strict aerobes
perform aerobic respiration only
final electron acceptor is oxygen (reduced to H2O)
strict anaerobes
perform anaerobic respiration (2)
final electron acceptor is an inorganic molecule
examples: nitrate (NO3-), Fe3+
strict anaerobes perform fermentation (2)
final electron acceptor is an organic molecule
examples: pyruvate (reduced to lactate)
acetyl-CoA (reduced to ethanol)
facultative anaerobes
can perform respiration and fermentation
most medically relevant bacteria
Gram positive bacteria in the mouth (4)
Streptococcus spp. cocci facultative anaerobes
Peptostreptococcus spp. cocci strict anaerobes
Actinomyces spp. rods strict/facultative
anaerobes
Lactobacillus spp. rods facultative anaerobes
Streptococcus spp. cocci
facultative anaerobes
Peptostreptococcus spp. cocci
strict anaerobes
Actinomyces spp. rods
strict/facultative
anaerobes
Lactobacillus spp. rods
facultative anaerobes