During photosynthesis, what role is played by the Sun's radiant energy? Explain your answer.

Answer 1

During photosynthesis, the Sun's radiant energy plays the crucial role of providing the energy source for the process. The energy from the Sun, in the form of sunlight, is absorbed by the pigment chlorophyll present in plant cells. This absorbed radiant energy is then utilized to convert carbon dioxide and water into glucose (a sugar molecule) and oxygen through a series of chemical reactions.

The energy from the Sun is used to power the light-dependent reactions, which occur in the thylakoid membrane of chloroplasts. Here, the absorbed radiant energy drives the transfer of electrons through an electron transport chain, resulting in the production of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH). ATP and NADPH act as energy carriers that provide the necessary energy to fuel the light-independent reactions.

The light-independent reactions, also known as the Calvin cycle, occur in the stroma of the chloroplasts. In this phase, ATP and NADPH produced during the light-dependent reactions are used to convert carbon dioxide molecules into glucose. The Sun's radiant energy is indirectly responsible for powering these reactions by providing the energy required to produce ATP and NADPH.

Overall, the Sun's radiant energy is essential for photosynthesis as it is the ultimate energy source that drives the conversion of carbon dioxide and water into glucose and oxygen, which are vital for the survival of plants and the subsequent energy flow within ecosystems.