Final answer:
Organisms convert energy to support life processes, with plants transforming sunlight into chemical energy and animals consuming organic molecules for energy. The first law of thermodynamics ensures conservation of energy, while the second law results in energy loss as heat during conversions.
Step-by-step explanation:
Living organisms engage in various energy conversions to maintain life processes. For example, green plants absorb radiant energy from the sun and convert it into chemical energy in the form of glucose, which is further used to synthesize carbohydrates, lipids, and proteins.
Animals, on the other hand, obtain their energy by consuming plants or other animals, thereby acquiring the chemical energy stored within organic molecules.
The process of energy conversion is governed by the laws of thermodynamics. The first law of thermodynamics dictates that energy cannot be created or destroyed, only transferred or transformed.
In contrast, the second law of thermodynamics states that energy transfers are not completely efficient, leading to some energy being invariably lost as heat, which cannot be used by organisms to perform work.
As energy flows through an ecosystem, autotrophs like plants capture energy directly from physical or chemical sources, converting it and storing it in organic molecules.
Heterotrophs, such as animals, then consume these molecules, obtaining energy for their own metabolic needs. However, since energy cannot be recycled, a constant input of energy is essential for life.