In photosynthesis, what is the main compound that is absorbed from the atmosphere?

In photosynthesis, the primary compound absorbed from the atmosphere is carbon dioxide. Plants, algae, and some bacteria use carbon dioxide, along with water and sunlight, to produce glucose and oxygen through the photosynthetic process. During this process, carbon dioxide enters the plant mainly through tiny openings called stomata in the leaves.

The incorporation of carbon dioxide is essential because it provides the carbon atoms needed for synthesizing glucose, which serves as an energy source for the plant and, by extension, for many other organisms in the ecosystem. This process not only fuels the growth and energy needs of the plant itself but also plays a crucial role in regulating atmospheric levels of carbon dioxide. Understanding the importance of carbon dioxide in photosynthesis emphasizes its role as a vital component in the Earth's carbon cycle and the maintenance of life on our planet.