Define the following vocabulary words in your own word:

intrinsic growth factors
extrinsic growth factors
acidophile
alkaliphile
stress proteins
sigma factors (proteins)
water activity (Aw)
oxidation-reduction potential (Eh)
oxygen toxicity
superoxide dismutase
peroxidase
catalase
fastidious
psychrotrophic
mesophilic
thermophilic
obligate anaerobe
aerotolerant anaerobe
bacterial fission
microbial biota
metabolism
catabolism
anabolism
chemotroph
chemoheterotrophs
transcription
translation
protein assembly