Introduction. 1  If you were a single-celled organism and you lived in a nutrient-rich place, staying alive would be pretty straightforward. 2  However, odds are you are not an amoebaâgiven that you're using Khan Academy right nowâand things arenât quite so simple for big, many-celled organisms like human beings.
The daily niacin requirement varies with the number of calories burned daily (the energy expenditure) and the protein intake. One niacin equivalent equals 1 mg of preformed niacin or 60 mg of dietary tryptophan. Niacin can be synthesized in the body from the essential amino acid tryptophan.Tissues can form an average of I mg of niacin from 60 mg of tryptophan provided by dietary protein. Consequently a high-quality protein diet supplies substantial tryptophan for niacin synthesis.he daily niacin requirement varies with the number of calories burned daily (the energy expenditure) and the protein intake. One niacin equivalent equals 1 mg of preformed niacin or 60 mg of dietary tryptophan. Niacin can be synthesized in the body from the essential amino acid tryptophan.
Amino acid synthesis is the set of biochemical processes (metabolic pathways) by which the various amino acids are produced from other compounds. The substrates for these processes are various compounds in the organism 's diet or growth media.Not all organisms are able to synthesise all amino acids.Humans are excellent example of this, since humans can only synthesise 11 of the 20 standard amino acids (aka non-essential amino acid), and in time of accelerated growth, arginine, can be considered an essential amino acid.ot all organisms are able to synthesise all amino acids. Humans are excellent example of this, since humans can only synthesise 11 of the 20 standard amino acids (aka non-essential amino acid), and in time of accelerated growth, arginine, can be considered an essential amino acid.