THE VITAMIN SOURCE AND OTHER GROWTH FACTORS

Vitamins are growth factors which fulfill specific catalytic needs in biosynthesis and are required in only small amounts. They are organic compounds that function as coenzymes or parts of coenzymes to catalyze many reactions. Table 11 itemizes the vitamins together with their active forms, catalytic function, molecular precursors, and rawmaterial sources.f  

Acccuory growth factor Active form Chemical group transferred Substance needed to fulfil metabolic reouiremeni Raw material source of growth factor 

Thiamin (vitamin B ) Thiaminepyro- phosphate Decarboxylation and aldehyde groups (i) Pyrimidine (ii) Thiazole (III) Pyrimidine + Thiazole (iv) Thiamine Rice polishings Wheat germ Yeast 

Riboflavin (vitamin B ) (i) Ravin mononucleotide (li) Flavin adenine dinucleolide Hydrogen Hydrogen (i) Riboflavin Cereals Cornsteep liquor Cottonseed flour 

Pytidoaal (vitamin B ) Pyrldoxal phosphate Amino group and decarboxylation (i) Pyridoxine (ii) Pyridoxamine or pyridoxal fiii) Pyridoxal phosphate PtnlcUlium spent mycelium Yeast Rice polishings Cere Wheat seeds Maize seeds Cornsteep liquor Cottonseed flour 

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