Elements and Compounds in Cells

Section 1: Elements and Compounds in Cells

Organisms constantly exchange substances with the external environment, acquiring the materials necessary for cellular activities from the inorganic natural world. Therefore, the chemical elements that make up cells can all be found in the inorganic natural world, with none of these elements being unique to cells. However, the relative proportions of these elements in cells differ greatly from those in the inorganic natural world.

Elements Constituting Cells

There are over 20 common chemical elements that constitute cells, with varying quantities for each element. Elements commonly found in cells include C, H, O, N, P, S, K, Ca, Mg, among others, termed as macroelements due to their higher quantities. Elements present in smaller amounts, such as Fe, Mn, Zn, Cu, B, Mo, are known as trace elements (microelements). From the data in the table, it can be observed that the elements C, H, O, and N are predominant in cellular composition, which is related to the compounds forming cells.

Compounds Constituting Cells

Most of the elements that constitute cells exist in the form of compounds, such as water, proteins, nucleic acids, carbohydrates, lipids, and more.

Please refer to Figure 2-1 for an understanding of the main compounds constituting cells and their relative proportions.

From the figure, it is evident that water is the most abundant compound in cells, while proteins are the most abundant organic compounds. Further chapters will provide detailed explanations on this topic.

The data in the figure is based on statistical results from various types of cells. In reality, the proportions of various compounds in cells vary significantly among different biological tissues, sometimes to a considerable extent.

This diversity also applies to the foods we consume. Due to the significant differences in types and quantities of nutrients in different foods, it is necessary to have a balanced diet that includes various foods to meet the body's nutritional needs. Our food comes from various biological tissues.