Basics of BiologyBasic Chemistry For Biology |
What are the most important elements in living systems? |
The most important elements in living systems include oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, and iron. These elements are essential to life due to their cellular function. The following lists the most common and important elements in living organisms:
Element |
Percent of Humans by Weight |
Functions in Life |
Oxygen |
65 |
Part of water and most organic molecules; molecular oxygen |
Carbon |
18 |
Backbone of organic molecules |
Hydrogen |
10 |
Part of all organic molecules and water |
Nitrogen |
3 |
Component of proteins and nucleic acids |
Calcium |
2 |
Part of bone; essential for nerves and muscles |
Phosphorus |
1 |
Part of cell membranes and energy storage molecules; part of bone |
Potassium |
0.3 |
Important for nerve function |
Sulfur |
0.2 |
Structural component of some proteins |
Sodium |
0.1 |
Primary ion in body fluids; essential for nerve function |
Chlorine |
0.1 |
Major ion in body fluids |
Iron |
Trace |
Component of hemoglobin |
Magnesium |
Trace |
Cofactor for enzymes; important to muscle function |