sejtPlazmamembránja

SejtPlazmamembránja, also known as the plasma membrane or cell membrane, is a biological membrane that separates the interior of all cells from the outside environment. It is composed of a phospholipid bilayer with embedded proteins. This structure is selectively permeable, meaning it controls the passage of substances into and out of the cell. The phospholipid bilayer consists of two layers of phospholipid molecules, with their hydrophilic heads facing outwards and their hydrophobic tails facing inwards. Embedded within this bilayer are various proteins, which perform a wide range of functions. These proteins can act as channels or carriers to facilitate the transport of specific molecules, serve as receptors for signaling molecules, or play roles in cell adhesion and recognition. The plasma membrane also contains cholesterol, which helps to regulate its fluidity, and carbohydrates, which are often attached to proteins or lipids and are involved in cell-cell recognition. The dynamic nature of the plasma membrane allows it to change shape and interact with its surroundings, playing a crucial role in maintaining cellular homeostasis and mediating cellular communication.