Cell Membrane Structure and Functions

A cell's plasma membrane demarcates the cell's borders and determines the nature of its interaction with the environment. Cells exclude certain …

Plasma membranes have integral transmembrane proteins involved in facilitated transport. These proteins are collectively referred to as transport …

Lipids are an essential component of all biological membranes. The average lipid content in mammalian membranes is 50%, though it can be as low as 20% in …

The plasma membrane is a dynamic barrier composed of lipids, proteins, and carbohydrates. It is the epicenter of many cellular processes required for cell …

The glycocalyx is a carbohydrate-rich, fuzzy-appearing layer on the outer surface of the cell membrane. It is highly hydrophilic, because of this it …

The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action …

Diffusion is a type of passive transport. In passive transport, a substance tends to move from an area of high concentration to an area of low …

The chemical and physical properties of plasma membranes cause them to be selectively permeable. Since plasma membranes have both hydrophobic and …

Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is …

Osmosis is the movement of free water molecules through a semipermeable membrane.  The water's concentration gradient across the membrane is …

Tonicity describes the amount of solute in a solution. The measure of the tonicity of a solution, or the total amount of solutes dissolved in a specific …

In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or …

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this …

The ER, Golgi apparatus, endosomes, and lysosomes work in tandem to modify, sort, and package proteins and lipids. An integrated membrane trafficking …

Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules …