secondary lysosome

Definition

Target type: cellularcomponent

Vacuole formed by the fusion of a lysosome with an organelle (autosome) or with a primary phagosome. [GOC:jl, ISBN:0815316194]

A secondary lysosome is a type of lysosome that has fused with another organelle, such as a phagosome or autophagosome, and contains the contents of that organelle in addition to the lysosomal enzymes. This fusion process brings the contents of the other organelle into the lysosome for degradation. The cellular component of a secondary lysosome is therefore a complex mixture of:
- **Lysosomal enzymes:** These are hydrolytic enzymes, such as proteases, lipases, and nucleases, that break down the components of the engulfed material.
- **Lysosomal membrane:** This membrane surrounds the lysosome and is responsible for maintaining the acidic pH of the lysosome and regulating the movement of substances in and out of the lysosome.
- **Engulfed material:** This is the material that has been taken up by the cell through endocytosis, phagocytosis, or autophagy and is now being degraded by the lysosome. This could include:
- **Phagosomes:** Vesicles containing engulfed particles, such as bacteria or cell debris.
- **Autophagosomes:** Vesicles containing damaged or worn-out organelles, such as mitochondria or ribosomes.
- **Other cellular components:** The secondary lysosome may also contain other cellular components, such as proteins, lipids, and carbohydrates, that are being transported or degraded.
The specific composition of a secondary lysosome varies depending on the type of material it has engulfed and the specific cellular function it is involved in.'
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Proteins (1)

Compounds (1)