microbial nutrition Flashcards
what two groups can nutrients be divided into
macronutrients and micronutrients
what are the macronutrients
C, H, O, N, S, P, K, Ca, Mg, Fe
how much macronutrients do we need
relatively large amounts
what percentage of the dry weight of the cell do macronutrients make up
95% of dry weight
what are the micronutrients
Mn, An, Co, Mo, Ni, Cu
how much micronutrients do we need
trace amounts
what three things do all organisms require (hint: __ source)
carbon source, electron source, and energy source
what two groups are organisms in according to their carbon source
heterotroph or autotroph
define heterotroph
use organic molecules as their carbon source
define autotroph
use carbon dioxide as their carbon source
what two groups are organisms in according to their energy source
phototroph or chemotroph
define phototroph
use light as an energy source
define chemotroph
use oxidation of chemical compounds as an energy source
what two groups are organisms in according to their electron source
lithotroph or organotroph
define lithotroph
use reduced inorganic substances as an electron source (ie H2S, Fe2+, NO2-)
define organotroph
use organic compounds as an electron source (ie glucose)
to name an organism with respect to carbon, electron, and energy source, what order do we put these three categories in
energy, electron, then carbon
how is oxygen obtained as a macronutrient
H2O, O2, and from organic compounds
what is N needed for in an organism
DNA, RNA, nucleotides, amino acid synthesis, + some carbs and lipids and enzyme cofactors contain N
how is nitrogen obtained as a macronutrient
organic molecules, ammonia, nitrate, atmospheric N (N2)
what is P needed for in organisms
needed in ATP, phospholipids, DNA, and some proteins
how is phosphorous obtained as a macronutrient
most organisms make use of inorganic phosphate and incorporate it directly into their cells
what is S needed for in organisms
to make some amino acids to make proteins, found in certain vitamins (ie biotin and thiamine)
how is sulfur obtained as a macronutrient
most microbes use sulfate as a source of sulfur after reducing it
what are growth factors
organic compounds + essential cell components that the cell cannot synthesize
how do we obtain growth factors
from the environment
T or F: all microbes require growth factors
false
define fastidious
refers to an organism that requires a lot of growth factors
what is a name for an organism that requires a lot of growth factors
fastidious
what are the three classes of growth factors
amino acids, purines and pyrimidines, and vitamins
