In biology, a reactant is a substance that takes part in and undergoes change during a chemical reaction. Reactants are the starting materials that are transformed into products through the process of the reaction. For example, in the process of photosynthesis, carbon dioxide and water are the reactants that are converted into glucose and oxygen.
Reactants are crucial in biological processes as they provide the necessary materials for reactions to occur. These reactions are essential for various life processes, including metabolism, energy production, and the synthesis of biomolecules.
Understanding reactants helps in studying how biological systems function and how different substances interact within living organisms.