This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Lysosomes

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Lysosomes are membrane-limited cytoplasmic organelles which contain enzymes. They are found in a wide variety of cells. They function in the digestion of substances brought into the cell from its environment, and in the degradation of cellular constituents.

Lysosomes are formed when part of the lipid bilayer containing enzymes buds off from a Golgi body. The membrane region demarcating the lysosome has active proton pumps traversing it; this enables the internal environment to be kept optimally acidic for enzyme activity.

Lysosomal enzymes include:

  • peptidases
  • nucleotidases
  • polysaccharidases
  • phosphatases
  • sulphatases

The primary lysosome becomes a secondary lysosome on fusion with an object, usually membrane-bound, that has to be digested. Examples include:

  • autophagocytosis: cell structure to be degraded becomes enclosed within endoplasmic reticulum membrane. The lysosome then fuses with this new vesicle.
  • phagocytosis: phagosome is membrane-bound and derived from the environment; lysosome fuses with it directly

Examples of lysosomes include the specific and azurophilic granules of neutrophils.

Defects in lysosomes can present as the lipid storage diseases.


Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.