How does the spongy mesophyll contribute to photosynthesis?

The spongy mesophyll contributes to photosynthesis by facilitating gas exchange and providing a large surface area for light absorption.

The spongy mesophyll is a layer of cells within the leaves of plants that plays a crucial role in photosynthesis, the process by which plants convert light energy into chemical energy. This layer is typically located beneath the palisade mesophyll and above the lower epidermis. It is characterised by its loose, irregularly-shaped cells that create large intercellular spaces. These spaces are filled with air and allow for the efficient exchange of gases, such as carbon dioxide and oxygen, between the leaf and its surrounding environment. This is particularly important for photosynthesis as carbon dioxide is one of the key reactants needed for the process.

In addition to facilitating gas exchange, the spongy mesophyll also contributes to photosynthesis by providing a large surface area for light absorption. The irregular shape and arrangement of the spongy mesophyll cells increase the internal surface area of the leaf, maximising the amount of light that can be captured and used in photosynthesis. This is particularly important as light is the primary source of energy for photosynthesis.

Furthermore, the spongy mesophyll cells contain chloroplasts, the organelles where photosynthesis takes place. These chloroplasts contain chlorophyll, a pigment that absorbs light energy and uses it to combine carbon dioxide and water to produce glucose and oxygen. The glucose is then used by the plant as a source of energy, while the oxygen is released into the atmosphere.

In summary, the spongy mesophyll plays a vital role in photosynthesis by facilitating the exchange of gases, providing a large surface area for light absorption, and housing the chloroplasts where photosynthesis occurs.