In active protein translation and folding.
Rough endoplasmic reticulum is called rough because<span> it has many ribosomes on its wall making it look rough. RER is</span><span> involved mainly in protein production, folding, and quality control. Smooth endoplasmic reticulum is specialised in fats and steroids production. </span><span />
        
             
        
        
        
Through Polymerization larger molecules are formed.
 
        
                    
             
        
        
        
<span>Receptors in muscles provide the brain with information about body position and movement. The brain controls the contraction of skeletal muscle. The nervoussystem regulates the speed at which food moves through the digestive tract.</span>