EVERYDAY SCIENCE

Detailed explanation-1: -Osmosis is a special type of diffusion, namely the diffusion of water across a semipermeable membrane. Water readily crosses a membrane down its potential gradient from high to low potential (Fig. 19.3 ) [4]. Osmotic pressure is the force required to prevent water movement across the semipermeable membrane.

Detailed explanation-2: -Exocytosis is a form of bulk transport during which large numbers of molecules are transported out of the cell. In exocytosis, a vesicle (a small, membrane-bound compartment) containing the molecules to be released fuses with the cell membrane, and the contents of the vesicle are expelled.

Detailed explanation-3: -Osmosis. Osmosis is the movement of water through a semipermeable membrane according to the concentration gradient of water across the membrane, which is inversely proportional to the concentration of solutes.

Detailed explanation-4: -The processes that determine molecular movement across membranes are diffusion, pinocytosis, carrier-mediated transport and transcellular transport [5].

Detailed explanation-5: -Osmosis: This is the hydrostatic force acting to equalize the concentration of water on both sides of the membrane that is impermeable to substances dissolved in that water. Water will move along its concentration gradient.