The process of photosynthesis occurs not on the surface layers of the leaf, but rather in a middle layer called the mesophyll (Figure 5.7). The gas exchange of carbon dioxide and oxygen occurs through small, regulated openings called stomata.Click to see full answer. In respect to this, which structure directly regulates the rate of photosynthesis in this plant? chloroplast Furthermore, how does Leaf shape affect photosynthesis? The shape of a tree’s leaves are a response to the tree species’ long term ecological and evolutionary histories. The leaf, then, is affected by these balancing acts: enough sunlight and carbon dioxide to run photosynthesis, but not too much associated heat absorption or water loss. People also ask, which part of the leaf carries out photosynthesis? The palisade mesophyll layer is made up of closely-packed, elongated cells located just below the upper epidermis. They contain chloroplasts and carry out most of the photosynthesis.How is photosynthesis regulated?The regulations of photosynthesis by light quality include regulations of stomatal movement, leaf growth, chloroplast structure, photosynthetic pigment, D1 protein and its gene and photosynthetic carbon assimilation by visible light, and effect of ultraviolet light on photosystem II in plant.