Animal Cell Diagram (Labeled)
A labelled diagram of an animal cell, with every organelle, what it does and how big it is.
What is an animal cell?
An animal cell is the basic building block of every animal, from a sponge to a human. Unlike a plant cell, it has no cell wall, so it is held together only by a thin, flexible membrane. That is why animal cells come in so many shapes: flat skin cells, long nerve cells and red blood cells squeezed into discs that fit through the narrowest capillaries.
Animal cells cannot make their own food. They take in glucose and oxygen from the blood, and their mitochondria release the energy by respiration. Cells that work hard, such as muscle and sperm cells, are packed with extra mitochondria for this reason.
Inside, the nucleus holds the DNA and sends instructions out to the ribosomes, which build proteins. The endoplasmic reticulum and Golgi apparatus fold, package and send those proteins where they are needed, and lysosomes break down worn-out parts so they can be recycled.
Animal cell organelles and their functions
| Organelle | What it does | Size |
|---|---|---|
| Cell membrane | A thin, flexible skin around the cell. It controls what goes in and out: food and oxygen in, waste out. | about 8 nm thick |
| Nucleus | Holds the DNA, the instructions for building and running the cell. It controls what the cell does by deciding which proteins get made. | about 6 µm across |
| Nucleolus | A dense spot inside the nucleus where ribosomes are put together. | about 1–2 µm |
| Mitochondrion | Releases energy from glucose by aerobic respiration (glucose + oxygen → carbon dioxide + water). Busy cells like muscle have thousands. | 1–2 µm long |
| Ribosomes | Tiny machines that read instructions copied from DNA and join amino acids together to make proteins. | about 25 nm |
| Rough endoplasmic reticulum | Folded membranes covered in ribosomes. Proteins made here are folded and sent on to the Golgi. | spreads through the cell |
| Smooth endoplasmic reticulum | Tubes without ribosomes that make fats (lipids) and help break down poisons. | a network of tubes |
| Golgi apparatus | Stacks of flattened sacs that sort, package and label proteins, then send them off in small bubbles (vesicles). | about 1–3 µm |
| Lysosome | A bag of digestive enzymes that breaks down worn-out parts and things the cell has swallowed. | 0.1–1 µm |
| Centrioles | A pair of short tubes that help pull the chromosomes apart when the cell divides. | about 0.5 µm long |
| Cytoplasm | The jelly that fills the cell. Most of the cell’s chemical reactions happen here, and the organelles float in it. | fills the cell |
Animal cell vs plant cell
Both have a nucleus, cytoplasm, membrane, mitochondria and ribosomes. Only plant cells have a cell wall, chloroplasts and a large vacuole: compare them on the plant cell diagram, or see a quick overview on the cell diagram page.
Open the same animal cell in 3D below: spin it, slice it open and pull each organelle out on its own.
Frequently asked questions
What are the parts of an animal cell?
Cell membrane, cytoplasm, nucleus (with a nucleolus), mitochondria, ribosomes, rough and smooth endoplasmic reticulum, Golgi apparatus, lysosomes and centrioles.
What does an animal cell not have that a plant cell has?
No cell wall, no chloroplasts and no large permanent vacuole. That is why animal cells are rounder and softer, and cannot make their own food by photosynthesis.
What does an animal cell have that a plant cell usually doesn’t?
Centrioles (which help the cell divide) and lysosomes (bags of digestive enzymes).
How big is an animal cell?
Most are 10–30 micrometres across: about a tenth of the width of a human hair, so you need a microscope to see one.
