Biological Membranes

These flashcards cover key vocabulary related to biological membranes, their structure, and functions.

Phospholipid

A molecule that has a hydrophilic head and hydrophobic tails, forming the basic structure of biological membranes.

Amphipathic

A property of molecules that possess both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts.

Lipid bilayer

A double layer of phospholipids that forms the fundamental structure of a cell membrane, creating a barrier between the inside and outside of the cell.

Membrane fluidity

The viscosity of the lipid bilayer that allows for the movement and rearrangement of its components.

Fluid-Mosaic Model

A model describing the structure of the plasma membrane as a mosaic of diverse protein molecules embedded in a fluid bilayer of phospholipids.

Integral proteins

Proteins that are embedded within the lipid bilayer and can extend across the membrane.

Peripheral proteins

Proteins that are attached to the exterior or interior surfaces of the membrane but do not penetrate the bilayer.

Cholesterol

A type of lipid that is amphipathic and helps maintain membrane fluidity at various temperatures.

Cytosol

The liquid component of the cytoplasm, which is water-based and viscous.

Glycoproteins

Proteins that have carbohydrate groups attached to them, which can play roles in cell recognition.

Fluidity determinants

Factors that affect the fluidity of the membrane, including the saturation of fatty acid tails in phospholipids.

Hydrophobic interactions

Forces that cause the hydrophobic tails of phospholipids to associate with each other, minimizing their exposure to water.

Polar amino acids

Amino acids with side chains that are hydrophilic and often found on the surface of membrane proteins.

Nonpolar amino acids

Amino acids with side chains that are hydrophobic and typically found in the interior regions of membrane proteins.

Signaling molecules

Molecules that transmit information between cells and are critical for cell communication.