Purdue University

Date:
1959-1960
Reference:
PP/CRI/E/1/8/5
Catalogue details

Licence: In copyright

Credit: Purdue University. Source: Wellcome Collection.

    23/97
    1Í3 5). Two-phase experiments. 6). Ion transfer, a rate problem« 7)o Criticisms examined. 8). Quantitative experiment on density of contact sites on root surface. Scope of inquiry Growth and iron accumulation Surface density of contact sites 9). Contact decomposition of Fe(OH)^ by roots« 10)o Diffusion coefficients of Fe in roots« 11)o Picture of root surface based on gel diffusion. 12). Summary o VITAMINS, ANTIBIOTICS AND GROWTH THOMAS H» JUKES, American Cyanamid Company, New York City, New York The vitamins are organic substances that are needed in small amounts in the diet of animals to prevent certain specific deficiency diseases» The following vitamins are necessary for the normal growth of one or more soecies* Vitamins A, B6^ B]_2, C, D, thiamine, riboflavin, nicotinic acid, pantothenic acid, folic acid and biotin«, It seems probable that during evolution animals have lost one or more of the enzymes needed, for the biosynthesis of each of these substances in effective amounts, except in the cases of vitamin D and nicotinic acid« The known biosynthetic mechanisms involved in the formation of the vitamins will be reviewed and discussed«, Most of the vitamins possess known coenzymatic functions that are suf ficient to account for their effects on growth® Some of the vitamins, such as riboflavin, nicotinic acid and pantothenic acid, are outstandingly versatile in the extent to which they participate coenzymatically in metabolic reactions. New findings have recently been described for biochemical reactions involving folic acid, vitamin B]_2 and biotin« The dependence of animals on their food for their supply of vitamins has led to some interesting ecological relation ships® No animal has shown less discrimination in the selection of food for nutritional adequacy than has the human soecies, which has suffered from xerophthalmia, scurvy, rickets, beri-beri, pellagra and nutritional anemia even though the foods needed to prevent these diseases have been readily