Nitrogen biochemical problems

This section presents selected examples of the use of nitrogen NMR in chemical and biochemical problems. Examples are meant to be illustrative rather than exhaustive. Additional applications may be found in previously cited sources (7,9,11). 

Figure 9.3 Plot of the base 10 logarithm of the apparent equilibrium constant K for the nitrogen fixation reaction (see reaction 9.5-2) versus pH at 298.15 K (see Problem 9.2). [With permission from R. A. Alberty, Arch. Biochem. Biophys. 389, 94-109 (2001). Copyright Academic Press.]...

VOCs react readily with nitrogen oxides especially imder favorable atmospheric conditions (intensive srmlight, high humidity, oxygenation, presence of transition metal species, etc.). To date, only few of the reactions are recognized, but the results of extensive studies focusing on the reactivity between NOa and the VOC parent compoimds in various biochemical systems are accessible and may be useful in solving environmental problems thus, the most relevant of these experiences are presented in this chapter. 

One of the most interesting of such examples of biochemical evolution in action has been demonstrated by Ernest Baldwin in his study of the nitrogen-elimination mechanism. It will be remembered that we have described the problem faced by the mammal in disposing of the nitrogen produced during the breakdown of protein this nitrogen exists in the form of ammonia, and ammonia is extremely poisonous even in very small quantities. Thus the animal, in order to avoid building up lethal quantities of ammonia, converts it instead into urea and excretes it in the urine. Not all... 

Various different substrates are being considered for the biochemical production of 1,3-propanedioI (see previous problem) using dissolved ammonia as the nitrogen source. Determine the maximum amount of... 

Reinbothe, H., Miersch, J., Mothes, K. Special problems of nitrogen metabolism in plants. Comprehensive Biochem. 19 A, 51-163 (1981)... 

The nucleotides which consist of three parts, namely a nitrogenous base, a pentose sugar and a phosphate radical, are a very important group of compounds since one or more of them is involved in virtually every biochemical process. The adenosine di- and tri-phosphates which play an essential part in cellular energy exchanges have a nucleotide-type structure as do many of the coenzymes. Furthermore, nucleotides constitute the monomeric units of which the nucleic acids are composed that is to say nucleic acids are polynucleotides. The nucleic acids which are of two types, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are responsible for directing the synthesis of proteins. They specify the unique sequence of amino acids in any particular protein and consequently should be regarded as primordial molecules on whose existence that of the proteins depends. However, since the synthesis of the nucleic acids depends on enzymes which are themselves proteins, this poses the fundamental evolutionary question as to which came first - the biochemical version of the problem of the chicken and the egg ... 

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