Final Answer:
Approximately 95% of living material consists of the four key atoms: carbon (_C_), hydrogen (_H_), nitrogen (_N_), and oxygen (_O_).
Step-by-step explanation:
Living organisms are primarily composed of organic molecules, and these molecules are built upon the foundational elements of carbon, hydrogen, nitrogen, and oxygen. The prevalence of these four atoms in living matter is a testament to their fundamental roles in biological processes.
Carbon, with its versatile bonding capabilities, serves as the backbone of organic molecules. Hydrogen is crucial for maintaining the overall structure of these molecules, often forming bonds with carbon to create hydrocarbons. Nitrogen is a key component of amino acids, the building blocks of proteins, and plays a vital role in genetic material like DNA and RNA. Oxygen is essential for cellular respiration, the process by which cells generate energy.
To quantify this composition, consider a representative example: the molecular formula for glucose, a fundamental sugar in biochemistry, is C₆H₁₂O₆. In this molecule, carbon accounts for 6 atoms, hydrogen for 12, and oxygen for 6. Together, these elements constitute the bulk of living matter. This formula is just one illustration; countless other organic molecules follow similar patterns, reinforcing the dominance of carbon, hydrogen, nitrogen, and oxygen in the vast majority of biological entities.
In summary, the 95% figure reflects the prevalence of these four essential atoms, highlighting their indispensable roles in the structure and function of living organisms.