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. Transport vesicles Transport vesicles can move molecules between locations inside the cell, e.g., proteins from the rough endoplasmic reticulum to the Golgi apparatus. Membrane-bound and secreted proteins are made on ribosomes found in the rough endoplasmic reticulum. Most of these proteins mature in the Golgi apparatus before going to their final destination which may be to lysosomes, peroxisomes, or outside of the cell. These proteins travel within the cell inside of transport vesicles. Secretory vesicles Secretory vesicles contain materials that are to be excreted from the cell. Cells have many reasons to excrete materials. One reason is to dispose of wastes. Another reason is tied to the function of the cell. Within a larger organism, some cells are specialized to produce certain chemicals. These chemicals are stored in secretory vesicles and released when needed. Types Synaptic vesicles are located at presynaptic terminals in neurons and store neurotransmitters. When a signal comes down an axon, the synaptic vesicles fuse with the cell membrane releasing the neurotransmitter so that it can be detected by receptor molecules on the next nerve cell. In animals endocrine tissues release hormones into the bloodstream. These hormones are stored within secretory vesicles. A good example is an endocrine tissue found in the islets of Langerhans in the pancreas. This tissue contains many cell types that are defined by which hormones they produce. Secretory vesicles hold the enzymes that are used to make the cell walls of plants, protists, fungi, bacteria and Archaea cells as well as the extracellular matrix of animal cells. Bacteria, Archaea, fungi and parasites release membrane vesicles (MVs) containing varied but specialized toxic compounds and biochemical signal molecules, which are transported to target cells to initiate processes in favour of the microbe, which include invasion of host cells and killing of competing microbes in the same niche. Extracellular vesicles Extracellular vesicles (EVs) are lipid bilayer-delimited particles produced by all domains of life including complex eukaryotes, both Gram-negative and Gram-positive bacteria, mycobacteria, and fungi. Types Ectosomes/microvesicles are shed directly from the plasma membrane and can range in size from around 30 nm to larger than a micron in diameter). These may include large particles such as apoptotic blebs released by dying cells, large oncosomes released by some cancer