Functions Of Plasma Membrane 1. The fluid nat | JEE NEET CORNER
Functions Of Plasma Membrane
1. The fluid nature of the membrane is important from the point of view of functions like call growth, formation of intercellular junctions, secretion, endocytosis, cell division, etc.
2. Plasma membrane allows the transport of the molecules across it. The membrane is selectively permeable to some molecules present on either side of it. The passage of substances across cell membranes occurs by various methods such as passive transport, active transport.
(i) Passive transport: Many molecules can move across the membrane without any requirement of energy and this is called the passive transport 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 the plasma membrane from higher to lower concentration. The movement of water by diffusion through membrane is called osmosis. As the polar molecules cannot pass through the non-polar lipid bilayer, they require a carrier protein of the membrane to facilitate their transport across the membrane.
(ii) Active transport: It is an uphill movement of materials across the membrane where the solute particles move against their concentration gradient i.e.. from their lower to higher concentration. Such a transport requires energy, which is obtained from ATP. Thus, it is an energy dependent process,
For example, Na+/K+ pump in animal cells.
