A cell is the smallest thing that all organisms are made of (excluding things like viruses). In multi-cellular organisms, cells are specialized. Certain cells do certain things. However, all or almost all cells contain the following parts:


The nucleus is the nuclear membrane, nucleolus, and the chromosomes, as a whole.


The nucleolus assists in the production of ribosomes.


In a cell, chromosomes contain genetically encoded information in the form of chromosomal DNA (deoxyribonucleic acid).

Nuclear Membrane

The nuclear membrane controls what gets in/out of the nucleus.

Nuclear Pores

Upon close observation, you will see that the nuclear membrane is not flat, but has many dips. These are nuclear pores, through which things going into/out of the nucleus pass.


Lysosomes help destroy worn parts, get rid of bacteria, and break down complex molecules. Lysosomes are actually specialized vesicles.

Golgi Apparatus

The Golgi Apparatus helps process/package/transport proteins.


Vesicles help transport things around the cell.

Rough Endoplasmic Reticulum

In a cell, the rough endoplasmic reticulum (ER), and the smooth ER extend all around the cell, and serve as a "highway" through the cell. The rough ER also modifies the proteins created by ribosomes.

Smooth Endoplasmic Reticulum

The smooth ER, unlike the rough ER, does not have ribosomes on it. The smooth ER is mostly involved in the synthesis of lipids and carbohydrates. The smooth ER also specializes in detoxification.


Ribosomes help in the synthesis of proteins. In a cell, many ribosomes are found floating freely in the cytoplasm, but many are also found on the smooth ER.


Mitochondria release energy, just like batteries. The energy is stored as ATP (adenosine triphosphate).


The vacuole stores food, water, minerals, proteins, and waste products. In some plants, vacuoles store chemicals that give the flowers their color.


In a plant cell, the chloroplast, which is green, performs photosynthesis. The energy released from photosynthesis is also stored as ATP.


In a cell, cytoplasm, which is 65% water, contains cell parts, enzymes, and dissolved nutrients. The water is a great environment for the biochemical reactions occurring inside the cell.

Cell Wall

The cell wall, found only in plant cells, gives the cell its shape. It allows plants to stand up without a skeleton or other support.

Plasma (Cell) Membrane

The plasma membrane, with its porous surface, controls what gets into/out of the cell. In its function, it is much like the nuclear membrane.


The cytoskeleton is composed of many thin fibers, and helps support the cell. The cytoskeleton can be disassembled and rearranged as needed.