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Dietary minerals are generally trace elements, salts, or ions such as copper and iron. Some of these minerals are essential to human metabolism. Vitamins are organic compounds essential to the body. They usually act as coenzymes or cofactors for various proteins in the body. Water is an essential nutrient and is the solvent in which all the chemical reactions of life take place. Main articles: Plant nutrition and Fertilizer Plants absorb nutrients from the soil or the atmosphere, or from water (mainly aquatic plants). An exception are the carnivorous plants, which externally digest nutrients from animals before ingesting them.[6] The chemical elements consumed in the greatest quantities by plants are carbon, hydrogen, and oxygen. These are present in the environment in the form of water and carbon dioxide; energy is provided by sunlight.[7] Nitrogen, phosphorus, and sulfur are also needed in relatively large quantities. Together, the "Big Six" are the elemental macronutrients for all organisms,[8] often represented by the acronym CHNOPS.[9] Usually they are sourced from inorganic (e.g. carbon dioxide, water, nitrate, phosphate, sulfate) or organic (e.g. carbohydrates, lipids, proteins) compounds, although elemental diatomic molecules of nitrogen and (especially) oxygen are often used. Other chemical elements are also necessary to carry out various life processes and build structures; see fertilizer and micronutrient for more information. Rich sources of copper: oysters, beef or lamb liver, Brazil nuts, blackstrap molasses, cocoa, and black pepper. Good sources: lobster, nuts and sunflower seeds, green olives, and wheat bran. Some of these are considered macronutrients in certain organisms. The mnemonic C. HOPKiN'S CaFe Mg (to be used as C. Hopkins coffee mug) is used by some students to remember the list as: carbon, hydrogen, oxygen, phosphorus, potassium, nitrogen, sulfur, calcium, iron, and magnesium. Silicon, chloride, sodium, copper, zinc, and molybdenum are sometimes also included, but are in other cases considered micronutrients.[10] |
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