Chapter 2 Review QuestionsLeigh Ann Foster Thursday Class1.The three main parts of cell structures are plasma membrane, cytoplasm, and nucleus.2.The plasma membrane is the outer boundary of the cell and it brings things in and out ofthe cell as needed. The nucleus of the cell is deep in the plasma membrane in the center of the cell which holds the DNA, which identifies what type of cell it is.The plasma membrane holds proteins and other molecules that are used to communicate with other cells in the body.3.The endoplasmic reticulum (ER) is an extensively folded network of canals and sacs made of cell membranes. The main function is protein synthesis.Ribosomes are small round sacs that are either attached to the RER or are free floating in the cytoplasm. It helps the protein synthesis process. The Golgi apparatus is stacks of folded up sacs. It takes the small bubbles of membrane called vesicles from the ER and continues the protein synthesis process.