There are several main ways of transporting substances through the cytoplasmic membrane: simple diffusion, facilitated diffusion, active transport and transport in a membrane package.
With simple diffusion, spontaneous movement of substances through the membrane from the region where the concentration of these substances is higher to the region where their concentration is lower is observed. Simple diffusion is relatively slow. To accelerate diffuse transport, membrane carrier proteins exist. They selectively bind to one or another ion or molecule and transfer them through the membrane. This type of transport is called light diffusion. A peculiar and relatively well-studied variety of membrane transport is transport in membrane packaging. Depending on the direction in which the substances are transferred (to or from the cell), two types of this transport are distinguished – endocytosis and exocytosis. Endocytosis is the absorption of external particles by a cell through the formation of membrane vesicles. With endocytosis, a specific section of the plasmalemma envelops the extracellular material and captures it, enclosing it in a membrane package. Exocytosis is the transportation of substances enclosed in a membrane package from the cell to the external environment.
Diffusion (simple and lightweight) – a variety of passive transport. It is characterized by the fact that substances are transported through the membrane without the expense of energy and only in the direction where a lower concentration of these substances is observed. Active transport – the transfer of substances through the membrane from a region of low concentration of these substances to a region of higher energy costs.
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