Organelle

Organelle is a specialized subunit, usually within a cell, that has a specific function. The name organelle comes from the idea that these structures are parts of cells, as organs are to the body, hence organelle, the suffix -elle being a diminutive. Organelles are either separately enclosed within their own lipid bilayers (also called membrane-bound organelles) or are spatially distinct functional units without a surrounding lipid bilayer (non-membrane bound organelles).

Structure and Function

Organelles are identified by microscopy, and can also be purified by cell fractionation. There are many types of organelles, particularly in eukaryotic cells. Among the more important are:

• the nucleus
• the mitochondria
• the chloroplasts
• the endoplasmic reticulum
• the Golgi apparatus
• the lysosomes
• the peroxisomes
• the centrosomes
• the vacuoles

History

The concept of organelles has been around since at least the mid-1800s, but the term "organelle" did not become common until the 1960s. The idea that certain properties of cells could be removed and then studied separately was a breakthrough in research.

See Also

• Cell
• Cell biology
• Cell compartment
• Cell nucleus
• Endomembrane system
• List of organelles

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  Electron micrograph of carboxysomes
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  Image of Brocadia anammoxidans