Lecture 10: Lysosome Flashcards
What is a lysosome?
A membrane bound organelle found in eukaryotes that contains numerous hydrolytic enzymes, capable of breaking down multiple types of macromolecules such as lipids, carbohydrates, and proteins.
What name was the lysosome given when it was first discovered?
‘The suicide sack’, due to its role in autolysis and apoptosis.
What other role does the lysosome play in the cell other than autolysis?
The lysosome also plays a role in the handling of endocytosed materials. Food particles, when taken into the cell are broken down into the base components for the cell to use or to excrete. The lysosome will fuse with an endocytosed vacuole and begin digestion. The recycling process involves digestion of worn out cellular components, and the products of digestion can be recycled for further use by the cell.
Who was Christian de Duve?
A Belgian biochemist born in 1917 and awarded a nobel prize in 1974. He played an important role in the discovery of the lysosome.
Christian de Duve was also responsible for the rediscovery of glucagon.
Aided in development of concepts such as autophagy and endo/exocytosis.
Describe the structure of a lysosome.
A phospholipid bilayer surrounds a hydrolytic enzyme mixture (peptidases, lipases, etc.). The contents of the lysosome has a very low pH of 4. These structure are typically 0.5 - 1 micrometres in diameter. Embedded in the membrane are lysosome-associated membrane glycoproteins (LAMPs). LAMPs play a role in the maintenance of low pH.
