An Inside Look: Lysosome By: Edward Huang and Tai Pham

Location In their simplest forms, lysosomes are visualized as dense spherical vacuoles. (Approx. diameter ranging up to one micrometer) They can display considerable variation in size and shape as a result of differences in the materials that have been taken up for digestion. This organelle is mainly found in animal cells but are sometimes found in plant cells

Background Information Formed by the function of transport vesicles budded from the trans-Golgi network with endosomes, which contain molecules taken up by endocytosis at the plasma membrane Carry about 50 different degradative enzymes that can hydrolyze proteins, DNA, RNA, polysaccharides, and lipids

Function Lyso- prefix: To loosen, dissolve, or free -some suffix: Body Functions as the Digestive System of the cell Can be considered a “police force” or “garbage disposer” Degrades materials that are taken up from outside the cell or digest obsolete compounds of the cell

Processes Endocytosis: Extracellular macromolecules are taken up into the cell to form membrane-bound vesicles called endosomes

Processes Phagocytosis: Carried out by cells called macrophages that engulf large extracellular particles (ex. dead cells or invaders) and target them for lysosomal degradation Autophagocytosis: Process which old organelles and malfunctioning cellular parts are removed from a cell

Products Products include amino acids and nucleotides They are recycled back into the cell for reassembly and reuse