Nutrition Flashcards
Important cations
K, Mg, Ca, Fe
Mg- enzyme activation
Fe- cytochromes, electron carrying proteins
Macroelements necessary for life
- needed to make carbohydrates, proteins, lipids, RNA, DNA
- SCHNOP(s)
- –sulfur, carbon, hydrogen, nitrogen, oxygen, phosphorus
Trace Elements
- found on glassware, water etc
Mn, Zn, Cu, Co, Mo, Ni
*found in enzymes and enzyme cofactors
Specialized requirements
Diatoms require silicic acid for cell wall (contains silica)
Micro organisms and Carbon Source
Used to make carbohydrates, other organic molecules
Ultimate source of C= CO2
Plants and microorganism can “fix” carbon dioxide
We can’t! We incorporate CO2 into organic compounds
Heterotrophs
Use preformed organic molecules as C source
Autotrophs
Principle C source is CO2
Microorganisms and Scavengers
Probably all naturally occurring organic molecules can be broken down by some microorganism ( plastics, DDT, degraded slowly if at all)
Some fastidious (1 molecule= carbon source)
Prototroph
Microorganism with typical nutritional requirements for its species
Auxotrophs
Mutation (lost ability to synthesize an essential molecule)
Phototroph
Uses light as energy source, traps light energy during photosynthesis (CO2 is sole C)
Chemotroph
Produces energy by oxidizing chemical compounds
Organotroph
Extracts electrons or protons from organic compounds
Lithotroph
“Rock eaters”
Reduces inorganic substances to produce electrons or protons
Photoorganotroph autotrophs
Photosynthetic, use organic molecules for electrons and hydrogen donors
Chemolithotrophic heterotrophs
Oxidize inorganic compounds, both for energy and as sources for electrons, hydrogen use CO2 as C source
Photolithotrophic heterotrophs
Photosynthetic, use water or other inorganic sources as electron donors, use CO2 as C source
Chemoorganotrophic autotrophs
Use organic compounds for energy, hydrogen, electrons as carbon donors
Nitrogen Requirments
Used for DNA and RNA, amino acids,
NH3 ammonia
NO3 nitrate, many bacteria reduce to NH3 , fertilize soil with nitrates
N2 “fixing” nitrogen, certain bacteria convert it to nitrate
Phosphorus Requirments
Used for amino acids, methionine and cytosine, some carbohydrates
Usually incorporated at SO4-
Defined Medium
Every compound and it’s concentration is known
E. Coil can grow in medium with only: Glucose Sodium phosphate Potassium phosphate Ammonium sulfate Magnesium sulfate Ferrous sulfate Calcium chloride pH 6.8
Complete Medium
“Enriched”
Amino acids, partially digested proteins, carbohydrates
Ex. TSB and TSA
Selective Medium
Selects for one kind of microorganism by inhibiting others
Ex Hektoen media contains salts, only those adapted will survive
Eosin, methylene blue (EMB) inhibit growth of gram +, only gram - grow
Inhibits gram-, only gram + will grow
Can medium be differential and selective? Explain!
Levine EMB agar
Medium has inhibitors of gram + growth
Medium also has lactose and dye, colonies that ferment lactose turn pink
