There exist chemical elements that are found in a greater quantity in the living organisms. They are:
- Oxygen: the most abundant element in living organisms. Humans is composed in a 65% of it.
- Carbon: the basis of all life on Earth. Living organisms are also refered to as carbon-based life forms.
- Hydrogen: the simplest element containing one proton and bonding easily with other elements.
- Nitrogen: composes around 80% of air on Earth. Very important in the plant life.
- Sulfur: component of cysteine and methionine, essential amino acids for living organisms.
- Phosphorus: used in the formation os phospholipids a major component of cell membrane of living organisms.
