Cell Structure Basics
The main parts of animal, plant and bacterial cells and what each part does.
A cell is the basic unit of life. Cells contain structures called organelles, each with a particular job.
Animal cell
- Nucleus: contains genetic material (DNA) and controls cell activities.
- Cytoplasm: a jelly-like substance where many chemical reactions occur.
- Cell membrane: controls what enters and leaves the cell.
- Mitochondria: where aerobic respiration releases energy.
- Ribosomes: where proteins are made.
Plant cell
Plant cells have all of the above and also:
- Cell wall: made of cellulose, gives strength and support.
- Permanent vacuole: contains cell sap and helps keep the cell firm.
- Chloroplasts: contain chlorophyll and carry out photosynthesis.
Bacterial cell
Bacteria are prokaryotes. Their DNA is not enclosed in a nucleus; it forms a loop in the cytoplasm and may include small rings called plasmids. They have a cell wall (not made of cellulose), a cell membrane and ribosomes.
Eukaryotes and prokaryotes
Animal and plant cells are eukaryotic: they have a nucleus. Bacterial cells are prokaryotic: no nucleus.
Comparison table
| Feature | Animal | Plant | Bacteria |
|---|---|---|---|
| Nucleus | Yes | Yes | No |
| Cell wall | No | Yes (cellulose) | Yes (not cellulose) |
| Chloroplasts | No | Some cells | No |
| Mitochondria | Yes | Yes | No |
Common mistakes
- Saying plant cells do not have mitochondria. They do, because plants also respire.
- Saying all plant cells have chloroplasts. Root cells, for example, do not.
- Describing the cell wall as controlling what enters and leaves. That is the job of the cell membrane.
Quick recap
Know what each organelle does, and the key differences between animal, plant and bacterial cells.