Cell Biology: Functions of Lysosomes

What is the function of lysosomes in a cell?

What does the root 'lys' in lysosome mean?

What is the process called when lysosomes digest molecules that are part of the cell itself?

What happens to the broken-down molecules after lysosomes finish digesting them?

What is an example of autophagy in the immune system?

What is broken down into individual amino acids by lysosomes?

What is the ultimate fate of the broken-down molecules by lysosomes?

What is the primary function of the acidic environment within a lysosome?

What would happen if many lysosomes were to burst simultaneously in a cell?

What is the main function of peroxisomes in liver cells?

What is the by-product of certain cellular enzyme activities that peroxisomes isolate?

What is the enzyme responsible for breaking down hydrogen peroxide in peroxisomes?

What is the pH of the cytoplasm in a cell?

Why is the acidic environment of lysosomes a safety mechanism for the cell?

What is the result of the breakdown of hydrogen peroxide by catalase in peroxisomes?

Lysosomes

Lysosomes are membrane-bound organelles that digest various molecules and substances within a cell.
The root "lys" means "to cut or digest".
Lysosomes have two main functions: Autophagy and Crinophagy.

Autophagy

Autophagy means "self-eating" and involves the digestion of molecules that are part of the cell itself or other cells.
Examples of autophagy include:
- Breaking down non-functional organelles, such as old mitochondria.
- Digesting engulfed bacteria and viruses in macrophages of the immune system.

Crinophagy

Crinophagy involves the digestion of excess secretory products.
Example: Breaking down excess hormones produced by a cell.
In both Autophagy and Crinophagy, the lysosomes release the broken-down molecules into the cytoplasm as building blocks, which can be reused by the cell.

Environment in Lysosomes

The enzymes in lysosomes, known as acid hydrolases, require an acidic environment to work properly.
The pH inside a lysosome is approximately 5, which acts as a safety mechanism for the cell.
If a lysosome were to burst, the acid hydrolases would not function properly in the cytoplasm due to its higher pH (approximately 7.4).

Peroxisomes

Peroxisomes are membrane-bound organelles responsible for various metabolic activities.
They are similar to lysosomes but have different functions.
Examples of peroxisome functions include:
- Lipid break down in some cells.
- Detoxifying chemicals and drugs in liver cells.
Peroxisomes contain enzymes, including catalase, which breaks down hydrogen peroxide into water and oxygen.
Hydrogen peroxide is a by-product of certain enzyme activities and is dangerous to the cell if not isolated and broken down.

Learn about the roles of lysosomes in cellular digestion, including autophagy and crinophagy. Understand how they break down molecules and substances within cells.