can flip phospholipids in only one direction but at other times, flip back and forth
Post translational modifications of proteins
Oligosaccharides placed onto the O of OH on a serine/threonine
Made of flattened cisternae
Sugars on the proteins also protect the protein from degredation
N and O glycosylation is done on phospholipids of lysosomes because they are exposed to harsh environments/ enzymes in the lysosomes
Receptors that recognize specific signal sequences in transport vesicles.
As vesicles bud, they are trafficked to specific organelle, plasma membrane, or secreted.
Two types of movement from the golgi
Movement of lysosomal enzymes that are generated in ER then trafficked to golgi, then trafficked to lysosomes
Specific signal stimulates synthesis
A regulated pathway
Transition vesicles take proteins that will undergo post-translational modification as well as then be tranfficked to particular regions after the golgi, then they move them to the golgi
From golgi to membrane, or organelles etc, are called secretory vesicles.
Acid environment (5.5ish)
Made of more than 40 different enzymes that can break apart molecules that are no longer toxic to cell or can be reused by cells.
Nucleic acids to nucleotides
Protieins to amino acids
Disaccharides/polysaccharides to monosaccharides
Phosphates from protein groups
Break down sulfate groups
Breaks down phospholpids
ATP hydrolysis and continual transport, active, of protons into lysosome.
Acidic environment is necessary for these enzymes
Requires energy to bring in H+
Contain Metabolic transporters
Pumps out individal materials, such as amino acids etc, into cytosol to be used by the cell
Need facilitated diffusion for this, a protein
Early endosomes are a sorting place for many components, they can act as a retrafficking/reuse receptor site that go to the membrane and bring ligands back to the cell, or continue to late endosomes, ~6.5ph as compared to cytosol 7ish
In late endosome, become more acidic 6ish, hydrolases are found in late endosomes, but less acidic that lysosomes
For complete degredation, late endosomes fuse with lysosomes and the lysosomes are sites with highly acidic environenment.
Vesicles undergo endocytosis
Endocytic vesicles are transported to early endosomes, a sorting place for many componenets
Can go to a late endosome which has a more acidic environment ~6
Manose receptrs outside are recognized by this and when they are bound they bud to endosomes and released due to acidic environment and then are broken down. Carried to late endosome or lysosomes
Cell surrounds constituents within cytoplasm through outpocketing of endoplasmic reticulum around the outside of dead old or dying organelles and creates a vacuole called an autophagosome, and it fuses with lysosome to make an autophagolysosome and enzyme of that can degrade organelle.
Means for cell to extend pseudopodia out and around foreign particles, bacteria, dying cells, and engulfed and fused. Formed into a vacuole that is called a phagosomes.
They are trafficked and fused to lysosomes to make a phago-lysosome.
Now the organelle can digest foreign material
Isolated organelles self-repliacate
Peroxisomes have characteristics of both categories of organelles
Can bud off of endomembrane system
Undergo fission event that allows the cell to make more of them, making them isolated organelles
Have an oxidative rather than acidic environment
Oxidizes particular constituents in cell that are toxic or to byproductst that are not toxic to be used
Catalase alters H2O2 so the cell can handle it.
Breaks down to H20 and O2
Take off H from organic compounds and generate H20 and an organic compound not damaging