1. The cell membrane is a thin but tough covering made of lipids and proteins that forms the outside of the cell. The cell membrane protects the inner contents of the cell, gives the cell shape and supports and controls what goes in and out of the cell.
2. The cytoplasm (means cell substance) contains water, various salts, and many large macromolecules. The cytoplasm also contains a variety of smaller subunits or compartments of the cell called organelles which perform various tasks.
3. The cell nucleus houses the cell’s genetic material (DNA and RNA) and proteins. The genetic material contains directions for making the cell’s proteins.
Eukaryotic cells are highly organized. They contain a variety of small subcellular structures called organelles. Organelles perform specialized tasks that are crucial to the cell's survival. Some organelles such as ribosomes and mitochondria are found in all eukaryotic cells. Other organelles perform specialized functions in specialized cells. For example, plant cells contain chloroplasts. Chloroplasts are the site of photosynthesis, the process whereby plant cell capture energy from light and store it in the form on chemical energy.