What is the single most abundant material in living matter?

The single most abundant material in living matter is water. Living matter is mostly made up of hydrogen, oxygen, carbon and nitrogen. These four elements make up 96.5% of the atoms in all living things. Two hydrogen atoms and one oxygen atom bond together to make up water.

The exact amount of water contained in a living organism’s mass varies, but it can be up to 90%. A human adult body is made up of 60% water. The brain, organs and muscle contain 70 to 85% water, while the skin contains 60%. The bones are composed of 31%. Water is essential to human function as it aids every body system.