Carboxyl groups have an electronegative oxygen atom double bonded to a carbon atom. This carbon-oxygen bond is very polar and the fact that its a double bond increases the polarity of the bond.
PEA agar, also referred to as Phenylethyl Alcohol Agar is a medium  used by microbiologists to grow microorganisms. The ingredient that  supplies nitrogen is casein. Making the world better, one answer at a time.
Fertilizers: Nitrogen is one of the most important ingredients in fertilizers, used for increasing soil fertility. It is used to make ammonia and urea, which are used as fertilizers to promote plant growth and increase yield.itrogen and its compounds have numerous uses and applications, right from making incandescent bulbs and fertilizers to a number of medications. In this article, a few of the most significant uses of this gas and its various compounds are discussed. Advertisement. Nitrogen is a chemical element with the atomic number 7.