Plant cell the major classes of cells and tissues of roots, stems, leaves, flowers, and reproductive structures, each of which may be composed of several cell types. Parenchyma cells are living cells that have functions ranging from storage and support to photosynthesis (mesophyll cells) and phloem loading (transfer cells). Apart from the xylem and phloem in their vascular bundles, leaves are composed mainly of parenchyma cells. Some parenchyma cells, as in the epidermis, are specialized for light penetration and focusing or regulation of gas exchange, but others are among the least specialized cells in plant tissue, and may remain totipotent, capable of
Double layer (biology) medium. In another feature, the cells are not in an equilibrium with the fluid bulk. There is a constant ion exchange between living cells and a fluid. Consequently, there is a difference in electric potentials between the cell interior and a fluid bulk, known as the transmembrane potential. This non-equilibrium potential affects the structure of the double layer. Double layer (biology) In biological systems, a double layer is the surface where two different phases of matter are in contact. Biological double layers are much like their interfacial counterparts, but with several notable distinctions. The surface of biological cells carry many