BIOL 200 Lecture Notes - Lecture 24: Lysosome, Low-Density Lipoprotein, Lipoprotein
Document Summary
Endocytosis allows the cell to maintain the size of the plasma membrane. Recall: new lipids and proteins are delivered to the plasma membrane via the secretory pathway (cell size increases and therefore needs to be regulated) There are three types of endocytosis: phagocytosis, pinocytosis, receptor-mediated. Amount of plasma membrane secreted = amount of membrane brought back in via endocytosis (occurs at the same time: phagocytosis important in most animals: I(cid:374) (cid:373)a(cid:373)(cid:373)als, 3 classes of wbc act as (cid:862)professio(cid:374)al phagocytes(cid:863): Macrophages (ingest cellular debris (aging & dead cells) and invading microbes) Regulation no required easy way to maintain cell/plasma membrane size. Does(cid:374)"t need coated vesicles happens more freely and easily. Take up unwanted molecules: receptor mediated endocytosis (rme, receptors used to collect specific extracellular compounds, clathrin used for vesicle formation. Ldl is a complex that makes lipids/cholesterol water soluble so they can be carried in the bloodstream. Receptors used to bring ldl into cells.
