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.
Phospholipids form the basic structure of a cell membrane, called the lipid bilayer. Scattered in the lipid bilayer are cholesterol molecules, which help to keep the membrane fluid consistent. Membrane proteins are important for transporting substances across the cell membrane.hospholipids form the basic structure of a cell membrane, called the lipid bilayer. Scattered in the lipid bilayer are cholesterol molecules, which help to keep the membrane fluid consistent. Membrane proteins are important for transporting substances across the cell membrane.