Secretory vesicles are transpoed ?
Ans. is 'd' i.e., Have no relation with concentration gradientExocytosisExocytosis is a reverse of endocytosis. This process is involved when secretory granules are extruded from the cell. When secretory vesicle comes in contact with inside of cell membrane, the membrane of the vesicle fuses with cell membrane and then there is extrusion of the contents of vesicle from the cells as secretory granules. Similar to endocytosis exocytosis requires Ca++ and energy. Exocytosis is also called emiocytosis or reverse pinocytosis.Exocytosis (secretion from the cell) occurs two pathways : -Non-constitutive pathway :- Proteins from the Golgi apparatus initially enter secretory granules, where processing of prohormones to mature hormones occurs before exocytosis. This pathway is sometimes called "regulated pathway". ii) Constitutive pathway :- Involves the prompt transpo of proteins to the cell membrane in vesicles, with little or no processing or storage.
Along concentration gradient
Against concentration gradient
May be along or against concentration gradient
Have no relation with concentration gradient