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.
Macro or major nutrients. Nitrogen (N), phosphorous (P) and potassium (K) are the nutrients your marijuana plants need in the largest quantity to thrive. These are listed on your nutrient package/bottle as N-P-K as a ratio.More detail on N-P-K fertilizer ratio.onsequently a fertilizer high in nitrogen is suitable for vegetative growth and one higher in phosphorous is suitable for flowering. Luckily all of this work has been done for you by the manufacturers. Ideally you will buy your hydroponic nutrients from a hydroponics shop where you will receive good advice.