Final answer:
The vast majority of a cell's dry mass consists of biological macromolecules, with carbon being the primary component, representing about 12% of the total dry weight and accounting for roughly 50% of the cell's total composition when excluding water.
Step-by-step explanation:
The vast majority of the dry mass of cells is made up of biological macromolecules. Although water comprises the bulk of a cell's total mass, when considering the dry mass, we look to carbon-based compounds. This is because carbon is the backbone of these molecules, which include carbohydrates, lipids, proteins, and nucleic acids. Carbon is so vital that it represents approximately 12 percent of the total dry weight of a typical cell and is a component of all macromolecules. In fact, it accounts for about 50% of the total composition of a cell when water is excluded.
These biological macromolecules are organic, containing not only carbon but often hydrogen, oxygen, nitrogen, and other minor elements. Nitrogen is another necessary element, playing a crucial role in the structure of amino acids and nucleic acids, though it doesn't make up as large of a percentage as carbon. Oxygen, similarly essential, is involved in cellular respiration and is part of many organic compounds within the cell.
About 99% of a cell's dry weight is made up of macronutrients such as hydrogen, carbon, oxygen, nitrogen, phosphorous, and sulfur, with other trace elements making up the remaining 1%. The structural complexity and functional diversity of cells are largely due to the versatility and abundance of carbon in biological macromolecules.