What part of all cells encases the cytoplasm and forms a boundary between the cell interior and cell exterior? DNA Endoplasmic reticulum Nucleus Cell membrane

The cell membrane, also known as the plasma membrane, is like a bouncer at a club, protecting the exclusive party inside—the cytoplasm—while controlling who gets in and out. It’s composed of a double layer of phospholipids, which gives it flexibility and functionality. With proteins embedded within, it not only serves as a barrier but also plays a critical role in communication and transportation, ensuring the cell’s needs are met. When it comes to real-world applications, understanding the cell membrane is crucial in fields like medicine and biotechnology. For instance, drug delivery systems are designed to effectively transport medications across the cell membrane to target specific diseases. Additionally, knowledge about how certain substances can pass through or be blocked by the membrane helps scientists develop better treatments and understand conditions like cancer or diabetes, where cellular signaling is often disrupted.