Microbes, eucaryotic

NO2" is toxic, it is likely (27,28) that the dissimilatory nitrate reductase functions at the membrane surface (as diagrammed in Figure 2) so that the N02" never enters the cell. Eucaryotic microbes also have NOg" and NO2" transport systems (29,30) whose function is regulated by the availabihty of NH4 (31) ... 

There are two classes of microbes, procaryotes and eucaryotes. Procaryotic cells are usually characterized by simple unicellular structures. Exceptions are also known such as the cyanobacteria, which are often multicellular. The only procaryotes are bacteria which are also the most abundant form of life on earth. Eucaryotes encompass all other forms of life, including animal and plant. 

O Day, D. H. and P. A. Horgen, Sexual Interactions in Eucaryotic Microbes, Academic Press, New York, 1981. 

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