Photosynthesis requires PHOTONS which are the elementary quanta of light. The energy of a photon is completely described by its color or wavelength. The intensity of light is related to the NUMBER of photons in a stream; it is the amplitude squared of the light treated as a wave.

So, the reactions to run photosynthesis depend on the number of photons or the intensity of light.

Light is an ingredient or “reactant” for making sugars through photosynthesis. Photosynthesis literally means “putting together from light.” With most chemical reactions, the more of a reactant you have, the faster the reaction is. Light energizes an electron which ultimately combines with carbon dioxide and water to make sugars. So the more light there is, the faster sugars can be made.

Light is a form of energy. Photosynthesis needs energy, to make sugar out of carbon dioxide and water. With more solar energy, there is more energy for more photosynthesis.

It's like the food energy we need to grow and move and think. If we have more food, we grow bigger.

Photosynthesis uses light as its fuel source. Without light, it has no energy.

Photosynthesis involves a special kind of chemical reaction that uses light as an energy source. In fact, the "photo" in the word "photosynthesis" means light. This is the same reason that particles of light are called photons.

When the right kind of photon hits a chlorophyll molecule, it triggers a chemical reaction that is crucial to photosynthesis. We call this chemical reaction the light-dependent reaction. The reaction that actually produces sugar, the light-independent reaction, cannot start until it has the product from the light-dependent reaction.