|MadSci Network: Cell Biology|
Six elements make up 98% of the mass of living organisms. They are: Hydrogen, Carbon, Nitrogen, Oxygen, Phosphorous, and Sulfer. There are trace amounts of other elements in living organisms including Sodium, Magnesium, potassium, calcium, manganese, iron, cobalt, copper, zinc, silicon and chlorine. Purves, et al., Life, The Science of Biology, 5th edition, 1998, page 21. All these elements are found in both animal and plant cells, since the types of molecules in all living cells on Earth contain a mix of these elements.
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