The composition of the human body can be classified as follows:
*Water
*Proteins
*Fats (or lipids)
*Hydroxyapatite in bones
*Carbohydrates such as glycogen and glucose
*DNA and RNA
*Inorganic ions such as sodium, potassium, chloride, bicarbonate, phosphate
*Gases mainly being oxygen, carbon dioxide
*Many cofactors.
The estimated contents of a typical 20-micrometre human cell is as follows: