Final answer:
Through photosynthesis, plants synthesize energy-rich carbohydrates like glucose, using carbon dioxide, water, and sunlight, which can then be stored for extremely long periods.
Step-by-step explanation:
The energy-rich compounds made through photosynthesis are usually carbohydrates, such as glucose. In this process, green plants use carbon dioxide (CO₂) and water (H₂O), along with the energy captured from sunlight, to synthesize glucose (C₆H₁₂O₆), which is an energy-rich compound used for long-term energy storage. The produced glucose molecules are stable enough to last for millions of years, which is exemplified by our current use of fossil fuels that contain energy from sunlight captured through photosynthesis millions of years ago.
Photosynthesis is the process by which plants make energy-rich compounds. During photosynthesis, plants use solar energy, carbon dioxide, and water to produce glucose, a carbohydrate, and oxygen. This process is essential for all life on Earth as it is the only biological process that captures sunlight energy and converts it into chemical compounds that organisms use for energy. The energy stored in the covalent bonds of sugar molecules through photosynthesis can last for hundreds of millions of years.