Final answer:
Cells remain alive by keeping their reactions far from thermodynamic equilibrium through a continuous input of matter and energy from their surroundings, never reaching a stale state which would lead to death.
Step-by-step explanation:
Cells maintain themselves in a steady state, with most of their reactions far from thermodynamic equilibrium; Cells accomplish this by having a continuous input of matter and energy from their surroundings.
Living cells operate as open systems, meaning they exchange both matter and energy with their environment. This constant exchange prevents cells from reaching chemical equilibrium, contrasting with closed systems, which eventually do. In equilibrium, the reactions have no net change over time, leading to insufficient free energy for cells to perform vital functions, resulting in death. Thus, cells remain far from equilibrium to maintain life. This is possible through the continuous input of matter and energy, primarily derived from foods broken down during metabolism or, more universally, from sunlight that plants use in photosynthesis to produce nutrients. These unceasing processes contribute to a steady state where the input and output rates of energy and matter are matched, allowing the cell to carry out its essential activities while persisting in its battle against increasing entropy, as dictated by the second law of thermodynamics. Without this energy input, they would succumb to entropy, leading to disorder and loss of structure necessary for life.