Different Levels Of Iron Research Articles

Binding of iron to amino acids and serum proteins in vitro.

SummaryFollowing incubation of 59Fe with pooled native human serum in vitro, ultrafiltrable iron was determined to be 5 to 7.5% of the total serum iron, at different levels of iron:albumin molar ratios. Under similar conditions approximately 2% of iron was ultrafiltrable when predialyzed serum was used. In physiological concentrations, additions of amino acids to predialyzed serum increased ultrafiltrable 59Fe to similar levels as that observed for native human serum. Histidine and lysine showed significant effects in this regard. Amino acids competed effectively with albumin and only to a lesser degree with transferrin for binding of iron, suggesting a tighter affinity of iron for transferrin.

Effect of Iron Nutrition on Root:Top Ratio1

AbstractRice (Oryza sativa L.) and two species of citrus (C. Aurantium and C. sinensis [Linn.] Osbeck) were grown in nutrient solutions at different levels of iron. Root:top ratios varied inversely as the level of iron nutrition, measured by iron supply and by leaf‐iron concentration.

The relative proportions of the chloroplast pigments as influenced by different levels of iron and potassium supply

1. Potato plants were grown in pot sand cultures at different levels of iron and potassium supply. Plants grown at the lowest level of iron developed iron deficiency chlorosis and potassium deficiency symptoms when maintained at the lowest level of potassium but not at the highest level. 2. Rapid procedures were developed for the extraction and estimation of chloroplast pigments from small samples of lamina—usually less than 1 g of fresh material. 3. The expression of pigment content on an area basis gave results which were in better agreement with visual observations than those expressed on either fresh or dry weight basis. 4. Both iron and potassium additions increased the chloroplast pigment content. Leaves exhibiting iron deficiency contained reduced quantities of all pigments per unit area of lamina. 5. A linear relationship existed between chlorophyll and carotene, chlorophyll and xanthophyll, and carotene and xanthophyll contents. 6. The results suggested that laminae completely deficient in chlorophyll would contain no carotene but might still contain xanthophyll. 7. The relative proportions of chlorophyll, carotene and xanthophyll do not remain constant under varying conditions of iron status. When iron is deficient the proportion of xanthophyll increased in relation to the chlorophyll and carotene contents.