What are photons?

Photons are the elementary particles of light and are crucial in the process of photosynthesis. They carry energy that can be absorbed by chlorophyll and other pigments in the photosynthetic tissues of plants. When photons strike these pigments, they excite electrons and initiate a series of biochemical reactions that ultimately convert light energy into chemical energy, allowing plants to produce glucose from carbon dioxide and water. This energy conversion is foundational to the process of photosynthesis, making it essential for plant growth and the energy supply for the entire ecosystem.

The other choices do not adequately represent what photons are or their role in photosynthesis. Atoms that compose glucose molecules relate to the product of photosynthesis rather than the energy source. Solutions that transport nutrients in plants refer to processes like osmosis or active transport but do not directly involve photons. Gas molecules produced during respiration pertain to the cellular process of breaking down glucose, which is a separate function from what photons contribute to plants during photosynthesis.