Search results
Results from the WOW.Com Content Network
A lysosome (/ ˈ l aɪ s ə ˌ s oʊ m /) is a single membrane-bound organelle found in many animal cells. [1] [2] They are spherical vesicles that contain hydrolytic enzymes that digest many kinds of biomolecules. A lysosome has a specific composition, of both its membrane proteins and its lumenal proteins.
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. [37] If a lysosome were to rupture, the enzymes released would not be very active because of the cytosol's neutral pH.
The ability of the lysosome to degrade a diverse set of cargo is attributed to the lysosomal lipase and other soluble hydrolases. These enzymes include sulphatases, phosphatases, peptidases, glycosidases, and nucleases. [3] The biochemical role of these enzymes are observed in various pathways, specifically in lipid catabolism.
These food vacuoles fuse with lysosomes which break down the components so that they can be used in the cell. This form of cellular eating is called phagocytosis. Lysosomes are also used to destroy defective or damaged organelles in a process called autophagy. They fuse with the membrane of the damaged organelle, digesting it.
Lysosomes and peroxisomes: Lysosomes contain digestive enzymes (acid hydrolases). They digest excess or worn-out organelles , food particles, and engulfed viruses or bacteria . Peroxisomes have enzymes that rid the cell of toxic peroxides , Lysosomes are optimally active in an acidic environment.
The process of creating vesicles within the endosome is thought to be enhanced by the peculiar lipid BMP or LBPA, which is only found in late endosomes, endolysosomes or lysosomes. [12] When the endosome has matured into a late endosome/MVB and fuses with a lysosome, the vesicles in the lumen are delivered to the lysosome lumen.
For example, following phagocytosis, the ingested particle (or phagosome) fuses with a lysosome containing hydrolytic enzymes to form a phagolysosome; the pathogens or food particles within the phagosome are then digested by the lysosome's enzymes.
Structurally, the lamp proteins consist of two internally homologous lysosome-luminal domains separated by a proline-rich hinge region; at the C-terminal extremity there is a transmembrane region (TM) followed by a very short cytoplasmic tail (C). In each of the duplicated domains, there are two conserved disulfide bonds. This structure is ...