Download LYSOSOME

By Benjamin Ha
What is a Lysosome?
 Lysosomes
are membrane-bound cell organelle
found in animal cells.
 Also known as suicide bags or suicide sacs by cell
biologist due to their autolysis
 Discovered by Christine de Duve in 1949
Function and Structure
 cellular
organelles
 contain acid hydrolase enzymes that break down
waste materials and cellular debris
 digest excess or worn-out organelles, food
particles, and engulfed viruses or bacteria
 the membrane around a lysosome allows the
digestive enzymes to work at a pH they require
 at a pH of 4.8, the lysosome’s interior is acidic
compared to cytosol which is basic(pH 7.2)
Function and Structure cont.
 it
maintains this pH by pumping protons from the
cytosol via proton pumps and chloride ion
channels
 the lysosomal membrane protects the cytosol and
the rest of the cell from degradative enzymes
within the lysosome
 the cell is protected from any lysosomal acid
hydrolases that gets drain into the cytosol because
the enzymes are pH sensitive and do not function
well or at all in alkaline environment of the cytosol
Formation
 Lysosomal
protein genes are transcribed
in the nucleus, then mRna transcripts exit
the nucleus into the cytsol, and ribosomes
translate it.
 When the mRNA exits the endoplasmic
reticulum and enters the Golgi apparatus,
a lysosomal tag(mannone 6-phosphate) is
added
Formation cont.
 The
tags are needed to allow mannose 6phosphate receptors to bind in the Golgi
apparatus
 This is crucial for proper packaging into
vesicles that are designated for the
lysosomal system
Disease
 Lysosomes
are responsible for lysosomal
storage diseases(LSD).
 Causes metabolisms disorders which is
due to the malfunction of one of the
enzymes.
 Rate of incidence: 1 in 5,000 live births