Final answer:
Living cells maintain a steady state known as homeostasis through metabolism, which involves energy-releasing and energy-requiring reactions. Cells are open systems that never reach chemical equilibrium, allowing them to constantly perform the energy-dependent tasks necessary for life. Photosynthesis is a crucial process that supplies the energy needed to fuel these biochemical reactions.
Step-by-step explanation:
Life is possible because living cells maintain themselves in a steady state known as homeostasis. The reactions within a cell are part of the cell's metabolism, which includes both energy-releasing and energy-requiring chemical reactions. These metabolic processes are necessary for the continuation of life, including essential functions such as organization, responsiveness, movement, growth, and reproduction.
Living cells are described as open systems, allowing materials to pass in and out. Therefore, they never reach chemical equilibrium, meaning they avoid the state where there would be no free energy to sustain life. This perpetual state away from equilibrium enables cells to carry on with the energy-dependent tasks essential for their survival. The conversion of sunlight into nutrients via photosynthesis is a critical source of energy for many living organisms, fueling the vast array of biochemical reactions in cells.
Understanding homeostasis is crucial since it explains how living organisms regulate internal conditions to keep them stable despite external environmental changes. For instance, human beings maintain a stable internal body temperature regardless of the external climate. Maintaining a constant internal environment is a key factor in good health and the successful operation of countless interconnected feedback systems in the body.