Cell Organelles
Your cells are not simple bags of fluid — they are highly organised cities, with specialised structures handling energy, manufacturing, waste disposal, and more. Click any organelle in the diagram to explore what it does.
Click to explore a structure
← Click to explore a structure
Organelle at a glance
| Organelle | Key role | Membrane |
|---|---|---|
| Nucleus | Stores DNA; controls gene expression | Double |
| Mitochondria | ATP synthesis via cellular respiration | Double |
| Rough ER | Protein synthesis and initial processing | Single |
| Smooth ER | Lipid synthesis; detoxification | Single |
| Golgi Apparatus | Protein modification and trafficking | Single |
| Lysosome | Intracellular digestion and recycling | Single |
| Centrosome | Microtubule organisation; spindle assembly | None |
| Peroxisome | Fatty-acid oxidation; H₂O₂ neutralisation | Single |
Key concepts
Division of labour
Each organelle is a specialist. The nucleus issues instructions, the ER and Golgi manufacture and ship proteins, and mitochondria supply the energy to run it all.
Membrane-bound
Most organelles are enclosed by a lipid bilayer that lets them maintain a distinct internal chemistry — different pH, enzyme concentration, or ion balance from the cytoplasm.
Endomembrane system
The nuclear envelope, rough ER, smooth ER, Golgi, lysosomes, and secretory vesicles are all physically or functionally connected — one integrated protein-trafficking network.
When organelles malfunction
Organelle failure underpins many diseases. Lysosomal storage disorders (e.g. Tay-Sachs) arise when hydrolytic enzymes are missing. Mitochondrial myopathies impair ATP production in muscle and nerve cells. Peroxisome biogenesis disorders (Zellweger syndrome) prevent very-long-chain fatty-acid breakdown. Understanding organelle biology is therefore directly relevant to medicine.