Why does palisade mesophyll have more energy-producing potential then spongy mesophyll??

Answer 1

The palisade mesophyll consists of a tightly packed group of slender cells containing a relatively large number of chloroplasts that circulate in a Ferris wheel like motion. This is called cyclosis. This circulation allows all chloroplasts to receive sunlight and not just the ones near the surface. These mesophyll cells resemble a picket fence just under the leaf's epidermis. This arrangement and positioning gives these cells the maximum advantage to trap sunlight and produce sugar and oxygen. The spongy cells are below the palisade cells, though a bit larger in size they do not have the concentration of the palisade cells. They also have air spaces among them making them less densely packed. If you compare the upper and lower surfaces of the leaf you will notice the darker green color on the top.

Answer 2

Palisade mesophyll is relatively dense. Also, in dicot leaves, the palisade mesophyll is closer to the leaf's upper surface than the spongy mesophyll - should get more sunlight exposure.