Lysosomes

https://www.youtube.com/watch?v=Ry30h1s7hqo

What are the key features of lysosomes

They contain powerful digestive enzymes such as proteases, these digest large molecules into smaller soluble molecules.

The internal fluid in a lysosome is acidic, this is because lysosomal enzymes have an optimum pH which is acidic

Functions of lysosomes

They play a key role in phagocytosis , e.g in white blood cells.

Can be used to destroy organelles that are damaged or no longer functional, In this case organelle is surrounded by vacuole and the lysosomes fuse with the vacuole membrane, Lysosomal enzymes now digest organelle

The digestion products are absorbed into the cytoplasm and can be reused to make new organelles

Sometimes lysosomes transfer their enzymes outside cell by exocytosis, e.g to digest and remove unwanted proteins or dead cells

What happens when a WBC is about to ingest bacteria

The WBC forms a vacuole around the bacteria , this is called phagosome

Lysosomes now fuse with the phagosome

The lysosomal enzymes now digest the bacteria and the soluble digestion products now pass into the cytoplasm

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