Biology 2382B Lecture 12: Cell Bio Midterm 2 Lecture Notes
Document Summary
Another important component of the secretory pathway is bringing things in from the cell surface: one reason is because we need to recycle membranes, cells need to internalize extracellular material. Pinocytosis: cell brings in small vesicles at the plasma membrane (usually vesicles containing liquid) small vesicles trap liquid and bring liquid into the cytoplasm, not all cells can do this either. But usually cells want to select what they are bringing in, so they want to use a receptor: use a receptor to bind to something on the outside to bring it in. Ldl (low-density lipoprotein) transferrin bring iron into the cell hormones (e. g. insulin), certain glycoproteins, etc: bring things across the plasma membrane, most of these do not cross the plasma membrane easily, have to be facilitated/transported across. Lipids are transported in large well-defined water-soluble complexes/particles called lipoproteins. Ldl receptors on plasma membrane (localized in clathrin-coated pits)
