What is the primary process by which plants convert sunlight into energy?

Photosynthesis is the primary process by which plants convert sunlight into energy. This process occurs primarily in the chloroplasts of plant cells, where chlorophyll captures sunlight and uses that energy to transform carbon dioxide from the air and water from the soil into glucose and oxygen. The glucose produced is a form of chemical energy that plants use for growth, reproduction, and other vital functions.

During photosynthesis, the light-dependent reactions convert sunlight into chemical energy in the form of ATP and NADPH, which are then used in the Calvin cycle to synthesize glucose. This not only fuels the plant but also serves as a fundamental source of energy for nearly all life on Earth, as plants form the base of the food chain.

This process is essential for the overall health of ecosystems, contributing to oxygen production and carbon dioxide absorption, thus playing a critical role in mitigating climate change and supporting biodiversity. In contrast, respiration, combustion, and decomposition involve the breakdown of organic matter rather than the synthesis of energy, highlighting why they are not the correct processes associated with the conversion of sunlight into energy in plants.