Editing Endomembrane system (section)

=== Lysosomes ===
{{main|Lysosomes}}

[[Lysosomes]] are organelles that contain hydrolytic enzymes that are used for intracellular digestion. The main functions of a lysosome are to process molecules taken in by the cell and to recycle worn out cell parts. The enzymes inside of lysosomes are [[acid hydrolases]] which require an acidic environment for optimal performance. Lysosomes provide such an environment by maintaining a pH of 5.0 inside of the organelle.<ref name=Alberts1>{{cite web|url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?highlight=Lysosomes&rid=mboc4.section.2363#2365|title=Transport from the Trans Golgi Network to Lysosomes|access-date=2008-12-09|last=Alberts|first=Walter| name-list-style = vanc |year=2002|work= Molecular Biology of the Cell 4th edition|publisher=Garland Science|display-authors=etal}}</ref> If a lysosome were to rupture, the enzymes released would not be very active because of the cytosol's neutral pH. However, if numerous lysosomes leaked the cell could be destroyed from autodigestion.

Lysosomes carry out intracellular digestion, in a process called phagocytosis (from the Greek {{lang|grc-Latn|phagein}}, to eat and {{lang|grc-Latn|kytos}}, vessel, referring here to the cell), by fusing with a vacuole and releasing their enzymes into the vacuole. Through this process, sugars, amino acids, and other monomers pass into the cytosol and become nutrients for the cell. Lysosomes also use their hydrolytic enzymes to recycle the cell's obsolete organelles in a process called [[autophagy]]. The lysosome engulfs another organelle and uses its enzymes to take apart the ingested material. The resulting organic monomers are then returned to the cytosol for reuse. The last function of a lysosome is to digest the cell itself through [[Autolysis (biology)|autolysis]].<ref name=Cooper6>{{cite web|url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?highlight=lysosomes&rid=cooper.section.1519|title=Lysosomes|access-date=2008-12-09|last=Cooper|first=Geoffrey| name-list-style = vanc |year=2000|work= The Cell: A Molecular Approach|publisher=Sinauer Associates, Inc}}</ref>