THE CELL
TRANSPORT INTO AND OUT OF THE CELL
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Large molecules
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Water
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Oxygen
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Helper protein
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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: -Osmosis is a passive transport process during which water moves from areas where solutes are less concentrated to areas where they are more concentrated.
Detailed explanation-3: -Osmosis is the net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane. A selectively permiable membrane is one that allows unrestricted passage of water, but not solute molecules or ions.
Detailed explanation-4: -The net movement of water (osmosis) is in the direction of increased solute concentrations. An easy way to visualize this rule is simply that the net water movement is from an area of high water concentration (little dissolved solute) to an area of low water concentration (high levels of solute).