No, chlorophyll is not the only molecule that absorbs light for photosynthesis. While chlorophyll is the primary pigment involved in this process, there are other pigments that also play a significant role.
In addition to chlorophyll a and chlorophyll b, which are crucial for capturing light energy, plants contain accessory pigments such as carotenoids and phycobilins. These pigments absorb light wavelengths that chlorophyll cannot, thus expanding the range of light energy that can be utilized for photosynthesis.
Carotenoids, for instance, absorb light in the blue and green wavelengths and reflect yellow, orange, and red, which is why we see these colors in many plants and fruits. They protect chlorophyll from damage caused by excess light and play a role in photoprotection. Phycobilins are found in red algae and cyanobacteria and also help in capturing light energy.
In summary, while chlorophyll is the main player in photosynthesis, it works alongside other pigments to maximize light absorption and contribute to the overall efficiency of the photosynthetic process.