Smooth ER<span>, by contrast, is not associated with </span>ribosomes<span>, and its </span>functions<span> differ. The </span>smooth ER<span> is involved in the synthesis of lipids, including cholesterol and phospholipids, which are used in the production of </span>new<span> cellular membrane.</span>
<span>The direction the nerve impulse travels relative to the central nervous system.
I hope this helps!</span>