phospholipid

(noun)

Any lipid consisting of a diglyceride combined with a phosphate group and a simple organic molecule such as choline or ethanolamine; they are important constituents of biological membranes

Related Terms

Examples of phospholipid in the following topics:

  • Phospholipids

    • Phospholipids are major components of the plasma membrane, the outermost layer of animal cells.
    • To qualify as a phospholipid, the phosphate group should be modified by an alcohol.
    • The cell membrane consists of two adjacent layers of phospholipids, which form a bilayer.
    • If a drop of phospholipids are placed in water, the phospholipids spontaneously forms a structure known as a micelle, with their hydrophilic heads oriented toward the water.
    • The phospholipid bilayer consists of two adjacent sheets of phospholipids, arranged tail to tail.

  • Fluid Mosaic Model

    • The fluid mosaic model describes the plasma membrane structure as a mosaic of phospholipids, cholesterol, proteins, and carbohydrates.
    • The main fabric of the membrane is composed of amphiphilic or dual-loving, phospholipid molecules.
    • Therefore, phospholipids form an excellent lipid bilayer cell membrane that separates fluid within the cell from the fluid outside of the cell.
    • The fluid mosaic model of the plasma membrane describes the plasma membrane as a fluid combination of phospholipids, cholesterol, and proteins.
    • This phospholipid molecule is composed of a hydrophilic head and two hydrophobic tails.

  • Membrane Fluidity

    • The mosaic nature of the membrane, its phospholipid chemistry, and the presence of cholesterol contribute to membrane fluidity.
    • The second factor that leads to fluidity is the nature of the phospholipids themselves.
    • If unsaturated fatty acids are compressed, the "kinks" in their tails elbow adjacent phospholipid molecules away, maintaining some space between the phospholipid molecules.
    • It lies alongside the phospholipids in the membrane and tends to dampen the effects of temperature on the membrane.
    • The plasma membrane is a fluid combination of phospholipids, cholesterol, and proteins.

  • The Plasma Membrane and the Cytoplasm

    • The cell membrane is an extremely pliable structure composed primarily of two adjacent sheets of phospholipids.
    • The phospholipid bilayer consists of two phospholipids arranged tail to tail.
    • The phospholipids are tightly packed together, while the membrane has a hydrophobic interior.
    • The phospholipid bilayer consists of two adjacent sheets of phospholipids, arranged tail to tail.
    • The eukaryotic plasma membrane is a phospholipid bilayer with proteins and cholesterol embedded in it.

  • The Endoplasmic Reticulum

    • The membrane of the ER, which is a phospholipid bilayer embedded with proteins, is continuous with the nuclear envelope.
    • The RER also makes phospholipids for cellular membranes.
    • If the phospholipids or modified proteins are not destined to stay in the RER, they will reach their destinations via transport vesicles that bud from the RER's membrane.

  • Steroids

    • Unlike phospholipids and fats, steroids have a fused ring structure.
    • It is a component of the plasma membrane of animal cells and the phospholipid bilayer.

  • Components of Plasma Membranes

    • Composed of a phospholipid bilayer with embedded proteins, the plasma membrane is selectively permeable to ions and organic molecules and regulates the movement of substances in and out of cells.
    • The plasma membrane is composed of phospholipids and proteins that provide a barrier between the external environment and the cell, regulate the transportation of molecules across the membrane, and communicate with other cells via protein receptors.

  • Chemiosmosis and Oxidative Phosphorylation

    • However, many ions cannot diffuse through the nonpolar regions of phospholipid membranes without the aid of ion channels.

  • Basic Structures of Prokaryotic Cells

    • The general structure of a cell membrane is a phospholipid bilayer composed of two layers of lipid molecules.
    • Archaeal phospholipids differ from those found in Bacteria and Eukarya in two ways.

  • Methods of Intracellular Signaling

    • Present in small concentrations in the plasma membrane, inositol phospholipids are lipids that can also be converted into second messengers.
    • Phosphatidylinositol (PI) is the main phospholipid that plays a role in cellular signaling.