what is catabolism and anabolism
catabolism is the breakdown of complex molecules
anabolism is the synthesis of complex molecules
what gradient must cells establish for function and what does this gradient allow them to do?
electrochemical gradient across cell membrane
-allows retention of nutrients, cell constituents, generation of energy
-enables transport (facilitated or otherwise)
what is required for microbial growth
-sufficent energy source and anabolic raw materials; mainly C, N, S & P
-needs trace elements such as certain metal ions and vitamins used as enzyme co-factors
what do bacteria cells use to capture iron molecules?
siderophores, some of the strongest known iron binding complexes, capture Fe+3 in low nutrient rich enviroments
what are the 3 main branches of microbe energy generation
-chemolithotrophy where inorganic compounds are utilised for energy generation such as elemental Sulfur
-Phototrophy where light particles are utilised for power generation such as photosynthesis
-chemoorganotrophy where organic compounds are broken down to generate energy such as reduced carbon compounds, this the branch that humans fall under
what are the 4 energy source gathering stategies of organisms
-phototrophy: photosynthetic, gaining energy from sunlight
-Chemotrophy: gaining energy from oxidation of chemicals, has 2 sub sections listed below
-chemolithotrophs: energy from oxidation of inorganic chemicals such as hydrogen sulfide, sulfur amonia, nitrates, hydrogen gas and iron
-chemoorganotrophs: gains energy from oxidation of organic molecules
what does the suffix ‘trophy’ mean in biology?
feeding/nutrition. refers to the type of energy and/or carbon acquisition strategies used by organisms
what are the two carbon source nutrition strategies used by organisms?
-autotroph: an organism that makes its own food by assimilating C-1 compounds (CO2 or CH4) and converting them to organic molecules
-hetrotroph: uses pre-formed organic molecules aquired from outside to generate energy and precursors for cell material. cannot make organic molecules from inorganic nutrients
what is oligotrophy and its importance
oligitrophy means small feeding and constitutes growth at low nutrient concentrations, soil often has 5-20 mg/l of dissolved organic C as opposed to the 800mg/l achieved in lab setting
what is syntrophy and its 2 types
syntrophy means ‘feeding together’
-obligate syntrophy involves a specialized, inseparable metabolic interdependence between two or more microbial species, where one partner’s survival relies on the other to remove inhibitory metabolic byproducts
-facultive syntrophy where microbes exchange metabolites to facilitate energetically unfavorable reactions, but unlike obligate syntrophy the partners can, under certain conditions, survive independently or switch to alternative, non-dependent metabolic pathways
how are xyloglucans (polysaccharide fibers) get digested and enter body in our gut
gut microbes called bacteroidetes digest them into short oligosaccharides, then to monosaccharides which can be integrated into intestine cells
what is catabolite repression
the ability of organisms to sense nutrients in enviroment and express genes for the catabolism of those nutrients
what is central metabolism
glycolisis, TCA cycle and ETC. the primary route for most organisms to gain their energy
what is fermentation and respiration in terms of substrate to end products? and the key product produced in all metabolism
fermentation: elctrons to organic porducts
respiration: electrons to inoragnic electron acceptor (like oxygen and nitrate)
production of energy carriers such as ATP and NADH and intermediates for biosynthesis
how can glucose be broken down and are most steps in glucolysis reversable
glucose can be broken down anaerobically via fermentation or aerobicly via respiration
most steps are reversible
what is secondary metabolism
metabolites not directly involved in growth development or reproduction, non-essential. often involved in ecological interactions, niche adaptation and signaling
what are photoautotrophs and an example
cyanobacteria (example)
uses hydrogen from water to reduce carbon dioxide to form carbohydrates producing oxygen gas. first organisms conducting oxygenic photosynthesis.
makes up a majority of marine plankton
what are chemoautotrophs
microorganisms that fix CO2 to make organic compounds. central role in global nitrogen cycle, degrading nitrate based fetilisers and biodegredation of organic pollutants
what are photoheterotrophs and an example
halobacteria (example)
potein bacteriorhodopsin vital in process, light energy transfers protons across the membrane out the cell, resulting proton gradient generates ATP giving halobacteria their colour, uses organic carbon but cant fix CO2
what are chemoheterotrophs and an example
E.coli, psudomonads
most common nutritional mode
uses organic carbon compounds for both carbon requirement and energy generation
most bacterial pathogens are chemoheterotrophs
what is the baas becking hypothesis and van niel hypotheses?
both hypothesis deal with the distribution and ecology of life
-baas backing theorises that everything is everywhere but enviroment selects
-van niel hypothesises that every molecule existing in nature can be used as a sorce of carbon or energy by a microorganism somewhere and microbes are found in every enviroment on earth
what is niche construction
organisms that shape the biochemical dimensions of their habitat
what are psychrophiles, thermophiles, hyperthermophiles, acidophiles, alkaliphiles, halophiles, halotolerant, barophiles and piezophiles, xerophiles?
microbes that thrive in:
-cold
-hot
-very hot
-acid pH
-alkali pH
-high NaCL conc
-sorta high NaCL conc
-high pressure conditions
-high pressure conditions
-enviroments with a lack of water
