What is a granum?

A granum is a specific structural feature found within the chloroplasts of plant cells, formed by a stack of thylakoids. Thylakoids are membrane-bound compartments that contain chlorophyll and other pigments, which are crucial for the process of photosynthesis. In essence, a granum facilitates the organization of these thylakoid membranes, allowing for efficient capture of light energy and progression of the light-dependent reactions of photosynthesis.

The arrangement of thylakoids into granum enables a larger surface area for light absorption, which enhances the plant's ability to convert solar energy into chemical energy. This structural feature is vital in the overall functioning of chloroplasts, contributing to the energy needs of the plant.

Understanding the function and significance of granum helps clarify its role in cellular processes, particularly those related to energy conversion in photosynthesis.