organelle membrane

Definition

Target type: cellularcomponent

A membrane that is one of the two lipid bilayers of an organelle envelope or the outermost membrane of single membrane bound organelle. [GOC:dos, GOC:mah]

Organelle membranes are highly dynamic structures that define the boundaries of organelles and compartmentalize cellular functions. They consist of a phospholipid bilayer, a fluid mosaic of lipids and proteins that provides a selective barrier between the organelle's interior and the surrounding cytoplasm.

The phospholipid bilayer is composed of two layers of phospholipid molecules, each with a hydrophilic head group facing the aqueous environment and a hydrophobic tail group facing the interior of the membrane. This arrangement forms a barrier that prevents the passage of most polar molecules.

Embedded within the membrane are a variety of proteins that perform specific functions, including:

- **Transport proteins:** These proteins facilitate the movement of molecules across the membrane, either passively or actively.
- **Receptor proteins:** These proteins bind to specific molecules, triggering intracellular signaling pathways.
- **Enzymes:** These proteins catalyze biochemical reactions within the organelle.
- **Structural proteins:** These proteins provide support and shape to the membrane.

The composition of organelle membranes varies depending on the organelle's function. For example, the plasma membrane, which surrounds the entire cell, is rich in cholesterol and phospholipids, while the mitochondrial membrane is highly enriched in proteins involved in oxidative phosphorylation.

Organelle membranes play a crucial role in maintaining cellular homeostasis. They regulate the passage of molecules, create compartments for specific biochemical reactions, and provide a surface for signal transduction and other cellular processes.'
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Proteins (9)

Compounds (81)