cell membrane

While proteins may contribute more by mass, phospholipids are the most numerous molecules.

Mosaic implies a diverse pattern of different components (proteins, lipids, carbs) packed together.

Small, non-polar molecules move easily through the non-polar lipid bilayer.

Plasmalemma is essentially the plasma membrane of a cell.

Membrane proteins can act as enzymes to catalyze reactions at the membrane surface.

Selective permeability ensures only specific molecules can pass, keeping internal homeostasis.

Amphipathic molecules are essential for forming the bilayer as they interact with both aqueous and non-aqueous environments.

The Na+/K+ pump moves ions against their gradients using ATP, defining it as active transport.

High heat increases the kinetic energy of lipid tails, increasing the membrane's fluidity.

Plasmalemma is a biological synonym for the plasma membrane.

Cholesterol intercalates between the fatty acid tails, stabilizing the membrane.

Lipids can self-seal due to the hydrophobic effect, reforming the bilayer automatically.

Simple diffusion occurs directly through the lipid bilayer for small, non-polar molecules.

The phosphate group is ionized and hydrophilic, ensuring the "head" interacts with the aqueous environment.

Peripheral proteins are bound to the surface, not embedded, making them easier to isolate.

Hormones and other signaling molecules bind to glycoprotein receptors on the cell surface.

The "kinks" created by double bonds prevent tight packing, which lowers the melting point and increases fluidity.

Maintaining concentration gradients against the electrochemical gradient necessitates active transport.

Standard plasma membranes are approximately 7.5 nanometers (or 75 Angstroms) in width.