Historical Examples. 1  It will be seen that the valves v on the other side of the annular chamber are closed. 2  The angle of the anterior chamber is a true angle and not an annular sinus. 3  Johnston suggests that the reference is to an annular eclipse which he finds occurred on August 14, at about 8Â¼ h. in the morning.
Cellular nutrients come in many forms, including sugars and fats. In order to provide a cell with energy, these molecules have to pass across the cell membrane, which functions as a barrier â but not an impassable one.
The Fluid Mosaic Model describes membranes as a fluid lipid bilayer with floating proteins and carbohydrates. Cell junctions are a special set of proteins that anchor cells together (desmosomes), occlude water passing between cells (tight junctions), and allow cell to cell direct communication (gap junctions).