Now that we have discussed the one universal structural element of cells, the cell membrane, we will begin reviewing the specific intracellular components found in eukaryotes, or multi-cellular organisms. Eukaryotes differ from prokaryotes in the level of their structural complexity. Whereas the simpler prokaryotes contain all their genetic material, such as DNA and RNA, within the cell membrane, eukaryotes have intracellular compartments enclosing different structures, called organelles, which contain different molecules and enzymes that perform various functions within and between cells.

In this section, we will discuss the function, structure, and location of intracellular compartments found in eukaryotic cells. With an understanding of these principles we can see how these components are necessary for cell life. While eukaryotic cells have increased structural complexity, prokaryotic cells are able to carry out most of the same processes with their simple structure. We will discuss what significance the different components have in eukaryotic cell life.

We will begin our discussion of eukaryotic intracellular components by discussing the structural roles of the cytoskeleton and cytosol. We will then discuss the biological function of various organelles, including the cell nucleus, mitochondria, peroxisome, endoplasmic reticulum, golgi apparatus, lysosome, endosome, and related structures. The nucleus and mitochondria house DNA and provide the cell with energy, respectively. Peroxisomes and lysosomes are responsible for degrading molecules within the cell. The endoplasmic reticulum, golgi apparatus, and endosomes are involved in cellular transport.