BIOB10H3 Lecture Notes - Lecture 4: Lysosome, Organelle, Lipid Bilayer Fusion

• School: UTSC
• Department: Biological Sciences
• Course: BIOB10H3
• Professor: Rene Harrison

Document Summary

Contains ~50 different hydrolytic enzymes made in. Range in size from 25 nm- 1 (cid:373) i(cid:374) dia(cid:373)eter. Digest contents brought into the cell by endocytosis or phagocytosis. During fertilization, the lysosome fuses with pm on sperm to release enzymes and digest egg"s outer (cid:272)overi(cid:374)g. Undigested and unwanted products- become residual body which either remains in cytoplasm or is exported by exocytosis. Altered as they pass through er & golgi. Proteins move to pm or are secreted from cell. Two types of secretory activity: constitutive, regulated. 1) constitute secretion synthesis & secretion into extracellular space occurs in continuous, unregulated manner. Process of membrane fusion & content discharge into the ecm. Luminal vesicle surface becomes part of outer cell membrane surface. Orti(cid:374)g sig(cid:374)als lead to (cid:862)(cid:272)argo(cid:863) protei(cid:374)s (cid:271)ei(cid:374)g loaded i(cid:374)to parti(cid:272)ular vesi(cid:272)les: vesicles bud via cop and clathrin proteins, vesicles told to fuse to next compartment by rab and snare proteins. Budding vesicles covered on cytosolic surface by protein coats: