When you’re looking at cells, the cytoplasm is where all of the action happens. This special fluid contains proteins that carry out a variety of functions in order to maintain homeostasis and promote cell growth. It also provides nutrients for cellular processes like protein synthesis and waste removal. The endoplasmic reticulum (ER) is an organelle found inside most cells as it transports molecules from one area to another while maintaining their shapes with its tightly-coiled membranes. The ER can be thought of as a long series of tubes that are connected by small openings called junctions which allow them to flow into each other freely without mixing up their contents or they may fuse together if there’s enough pressure on either side