Chemical element, the content of which in the cell is 17%.

All living organisms are made up of cells that have a similar chemical composition:

Macronutrients:

Oxygen (65-75%), carbon (15-18%), hydrogen (8-10%), nitrogen (1.5-3%) (in general, about 98%);
Potassium, calcium, sodium, sulfur, magnesium, iron, phosphorus, chlorine (tenths and hundredths of the cell composition).
Trace elements: fluorine, iodine, copper, zinc, which are represented by hundredths and thousandths of a percent.

Carbon makes up 17% of a cell’s chemistry.