Lysosome

What are lysosomes?

• Membrane-bound organelles

• Contain digestive enzymes

• Break down waste, debris, and pathogens

What is the main function of lysosomes?

• Act as the cell’s recycling center

• Digest old/damaged organelles

• Break down macromolecules

• Destroy invaders (e.g., bacteria).

In which type of cells are lysosomes found?

• Animal cells

What type of enzymes do lysosomes contain?

Hydrolytic enzymes that include:
Proteases
Nucleases
Lipases
Function best in acidic conditions.

How do lysosomes form?

Formed by the Golgi apparatus:
Packages enzymes into vesicles
Vesicles become lysosomes.

What types of molecules do lysosomes break down?

Proteins
Lipids
Carbohydrates
Nucleic acids
Pathogens and cellular debris.

What is the pH inside a lysosome?

About 4.5–5.0
Acidic environment for optimal enzyme activity.

What is autophagy?

Lysosomes digest the cell’s own damaged parts
Recycles components for reuse.

What is phagocytosis?

Cell engulfs large particles or microbes
Forms a vesicle (phagosome)
Phagosome fuses with lysosome for digestion.

What happens to the waste after digestion?

Useful materials are recycled
Undigested waste expelled via exocytosis.

What is the role of lysosomes in immunity?

White blood cells use lysosomes to:
Destroy engulfed bacteria/viruses
Aid in immune defense.

What is the connection between lysosomes and genetic disorders?

Lysosomal storage diseases (e.g., Tay-Sachs):
Caused by missing/faulty enzymes
Lead to buildup of undigested substances
Result in cellular damage and disease.

How do lysosomes protect the rest of the cell from their enzymes?

Enzymes enclosed in a membrane
Only active in acidic pH (inactive at cell's neutral pH).

What is the difference between lysosomes and peroxisomes?

Lysosomes:
Use hydrolytic enzymes
Break down macromolecules and pathogens
Peroxisomes:
Use oxidative enzymes
Break down fatty acids
Detoxify hydrogen peroxide and other toxins.

What happens during lysosomal rupture or leakage?

Enzymes can damage or kill the cell (lysis)
May occur during apoptosis (programmed cell death)
Uncontrolled rupture may lead to disease or inflammation.