| 释义 |
essential element
essential element n (Biochemistry) biochem any chemical element required by an organism for healthy growth. It may be required in large amounts (macronutrient) or in very small amounts (trace element). See also macronutrient, trace element essential element
essential element or mineral element an element without which normal growth and reproduction cannot take place. In plants, there are seven major essential elements: nitrogen, phosphorus, sulphur, potassium, calcium, magnesium and iron. There are also TRACE ELEMENTS required in much smaller quantities, for example, manganese, boron, chlorine. Animals also have requirements for elements, the list being quite similar to that for plants. |