This is related to the angular diameter distance, which is the distance an object is calculated<span> to be at from and , assuming the Universe is </span>Euclidean<span>. The actual relation between the angular-diameter distance, , and redshift is given below.</span>
The primary function of the plasma membrane is to protect the cell from its surroundings. Composed of a phospholipid bilayer with embedded proteins, the plasma membrane is selectively permeable to ions and organic molecules and regulates the movement of substances in and out of cells.
