Photosynthesis is the remarkable process that allows plants to create their own food using sunlight, water, and carbon dioxide.
The detailed process of light-dependent reactions in photosynthesis begins when sunlight hits special pigments in the chloroplasts, particularly chlorophyll. These pigments capture light energy and convert it into chemical energy. Inside the thylakoid membranes, water molecules split into hydrogen ions, electrons, and oxygen gas. The electron transport chain role in photosynthesis then comes into play as electrons move through a series of proteins, creating a flow of energy. This movement generates ATP (adenosine triphosphate) and NADPH, which are essential energy-carrying molecules. The oxygen released during this process is what we breathe in the air.
The Calvin Cycle transformation in photosynthesis represents the second major phase, where plants use the ATP and NADPH created during the light-dependent reactions to produce glucose. This process occurs in the stroma of chloroplasts and doesn't require direct sunlight. Carbon dioxide from the air enters the leaves through tiny pores called stomata. Through a complex series of chemical reactions, the carbon dioxide combines with a compound called RuBP (ribulose bisphosphate). An enzyme called rubisco helps transform these molecules into simple sugars. The cycle continues as more carbon dioxide enters the leaf, allowing the plant to produce the glucose it needs for growth and energy storage. This glucose can later be converted into other types of sugars, starches, and cellulose that the plant uses to build its structures and store energy for later use.
