Universal Characteristics of Cells (all Life)
   
1.  all cells store their hereditary information in DNA

2.  all cells replicate their hereditary info via templated polymerization
                                

3.  all cells transcribe hereditary info into intermediate RNA via templated transcription

4.  all cells translate RNA in same mechanistic way via codon:anticodon "Chargaff" pairing 
                                                            
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 5.  all cells regulate rate of gene transcription/translation, so only a portion of full
         repertoire of possible RNA's/proteins are copied, thus hereditary info dictates
         not only nature of cell's proteins, but also when/where they are to be made
                                           (differential gene activity)
 6.  all cells use protein catalysts (enzymes) to make/break covalent bonds
                                      E  +   S    <--->    ES    <--->   E  +   P
 7.  all cells metabolize - consume free energy and are far from chemical equilibrium.
     consumption of free energy creates covalent bonds (which resists the disordering
     effects of thermal motion), thereby creating hereditary info in a DNA sequence.
          the methods that cells have evolved to obtain free energy include:
                 heterotrophy - oxidation of foods (covalent bonds)
                 autotrophy - capture of light energy via pigments (photosynthesis)
                 lithotrophy - chemical electron donors provide energy
           N₂ & CO₂ are stable and unreactive & reduction to NH₂ & CH₂O uses energy.
   
8.  all cells are enclosed in a spontaneously aggregating amphiphilic phospholipid bilayer:
     membranes regulate nutrient/water transfer, concentrate molecules internally,
     all membrane have embedded protein transport molecules
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