cell membrane

Carrier proteins bind specific molecules and shift conformation to move them across the membrane.

Peripheral proteins sit on the outside (or inside) surface of the bilayer.

Both facilitated and simple diffusion are passive processes driven by concentration gradients.

Cholesterol is a steroid, characterized by its four-ring hydrocarbon structure.

Immune cells use recognition markers to identify infected or foreign cells (e.g., pathogens).

Its ability to regulate its own composition and environment is a fundamental property of a living membrane.

Pinocytosis is a type of endocytosis where the membrane invaginates to take in fluid.

The cell membrane's surface markers are crucial for identifying "self" vs "non-self" cells.

Saturated chains pack tightly, resulting in a more rigid, less fluid membrane.

The phosphate group is negatively charged and highly attracted to water.

Glycoproteins and glycolipids on the surface form the glycocalyx, involved in cell adhesion.

It is passive (no ATP) but uses a protein facilitator.

Many peripheral proteins are connected to the cytoskeleton on the cytoplasmic side of the membrane.

Plants typically have higher levels of unsaturated fats to adapt to ambient temperatures.

Singer and Nicolson proposed the Fluid Mosaic Model in 1972.

Most cytoskeletal anchors are peripheral proteins attached to the cytoplasmic surface.

The fatty acid tails create a hydrophobic region that prevents passage of polar substances.

The Robertson model (Unit Membrane) described a fixed, trilaminar structural arrangement.

Because facilitated diffusion uses a limited number of proteins, the rate can reach a maximum (saturation).