Lysosomes (or vesicles) are membrane enclosed bubbles within the cell that contain enzymes and proteins that are found in almost every cell. They are formed when bubbles carrying enzymes break off from the Golgi body and fuse with other bubbles full of acid that activate the enzymes. They are important in:
- Waste disposal – Lysosomes can help break down damaged cellular components including proteins and organelles. In this way, they help keep a clean and functioning cell.
- Secretion – Lysosomes help cells secrete proteins outside of the cell. These can be important for sending messages to other cells.
- Energy storage and metabolism – Lysosomes help to store nutrients and break them down for when the cell needs energy. In plant cells, they can store water and are known as vacuoles.
- Defence – Lysosomal enzymes are important in helping immune cells break down bacteria and viruses during infection. Without them, many of the immune cells would have a difficult time killing off the invaders.
- Cell suicide – When cells have hit the end of their life span or need to be killed off, it must be done in an efficient way called apoptosis. Lysosomes play a vital role in this by engulfing cellular parts and breaking them down in a clean, efficient way. If lysosomes don’t do their job, cell death is messy (necrosis) and can cause inflammation and disease.
When lysosomes don’t function properly they cause a whole host of disorders with no direct treatment options. One particular disease is called Gaucher’s disease and is caused by the lack of a single enzyme which causes fat to build up in white blood cells. This in turn affects the person’s spleen, liver, kidneys, lungs, brain and bone marrow.
The importance of these small bubbles cannot be overstated.