Savannah Holly. This holly grows quickly in full sun or partial shade on moist, acid soils. Growth is poor and foliage chlorotic on alkaline soil. Plants in full sun can grow a dense canopy, those in partial shade are more open. This plant is considered mostly allergy free and causes little or no allergy problems in most people. Trees attract cedar waxwings, mockingbirds, robbins and many other birds. A severe witches broom-like disease caused by Sphaeropsis fungus attacks and kills Ilex x attenuata cultivars in parts of Florida.
apical membrane, the layer of plasma membrane on the apical side (the side toward the lumen) of the epithelial cells in a body tube or cavity, separated from the basolateral membrane by the zonula occludens. 1  Facebook.
Cell membranes are composed of a bimolecular layer of phospholipids and cholesterol, with hydrophilic and hydrophobic regions. Peripheral proteins move along the surfaces and integral proteins are embedded in the lipid bilayer. Some integral proteins extend through both layers (transmembrane proteins). Many of these are glycoproteins with surface carbohydrate units. The cell membrane is the site of the sodium ion pump which maintains cell volume by pumping sodium out of the cell. The outer plasma membrane is permeable to ions, but not to larger molecules. It is also the site for hormone-receptor and cell signal interaction.