AP BIOLOGY

Detailed explanation-1: -The binding of Ca2+ ions to specific sensors then triggers the secretory vesicles (called synaptic vesicles) to fuse with the plasma membrane and release their contents to the extracellular space.

Detailed explanation-2: -Secretory vesicles are transported to specific sites at the plasma membrane, where they dock and fuse to release their contents. Similar to other cellular processes, cell secretion is found to be highly regulated and a precisely orchestrated event.

Detailed explanation-3: -Exocytosis is the process by which cells move materials from within the cell into the extracellular fluid. Exocytosis occurs when a vesicle fuses with the plasma membrane, allowing its contents to be released outside the cell.

Detailed explanation-4: -Transport of the mature secretory vesicle to the site of release at the cell membrane is microtubule-dependent and mediated by carboxypeptidase E. Carboxypeptidase E is a transmembrane protein whose cytoplasmic tail binds to the adaptor protein dynactin, which tethers the vesicle to the motor proteins kinesin-2 or-3.

Detailed explanation-5: -Vesicles Travel Cellular Highways To help organize these vesicles and get them pointed in the right direction, the cell uses the rigid filaments and tubes of the cytoskeleton. Special motor proteins attach to cargo-filled vesicles and carry them along the cytoskeleton like trucks on a highway.