Consider the following statements regarding transport system in cell: 1. Molecules can move briefly across the membrane without any requirement of energy and this is called the active transport. 2. Water moving across the cell membrane from higher to lower concentration is called osmosis. Which of the statements given above is/are correct?

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AhmedNazir · Answer 1 · Sep 04, 2022 04:29:57

Option 2 : 2 only

One of the most important functions of the plasma membrane of the cell is transport of the molecules across it.
The membrane is selectively permeable to some molecules present on either side of it.
Many molecules can move briefly across the membrane without any requirement of energy and this is called the passive transport. Hence statement 1 is not correct.
Neutral solutes may move across the membrane by the process of simple diffusion along the concentration gradient, i.e., from higher concentration to the lower.
Water may also move across this membrane from higher to lower concentration. Movement of water by diffusion is called osmosis. Hence statement 2 is correct.
As the polar molecules cannot pass through the nonpolar lipid bilayer, they require a carrier protein of the membrane to facilitate their transport across the membrane.
A few ions or molecules are transported across the membrane against their concentration gradient, i.e., from lower to the higher concentration.
Such a transport is an energy dependent process, in which ATP is utilised and is called active transport, e.g., Na+/K+ Pump.

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