Cell Surface Membranes and the Fluid Mosaic Model

Vocabulary flashcards reviewing membrane lipids, the phospholipid bilayer, membrane functions, cholesterol, and the fluid mosaic model based on the lecture notes.

Triglyceride

A lipid molecule consisting of three fatty acid molecules bonded to one molecule of glycerol, which is nonpolar and hydrophobic.

Phospholipid

A lipid molecule consisting of two hydrophobic fatty acids and a polar, highly charged hydrophilic phosphate group bonded to a glycerol molecule.

Hydrophobic

Refers to nonpolar substances or regions that are insoluble in water and avoid interaction with water, such as fatty acids.

Hydrophilic

Refers to polar or charged substances or regions that are attracted to and can interact with water, such as phosphate groups.

Phospholipid bilayer

A double-layer structure formed in water where hydrophilic phosphate groups face outward to interact with water while hydrophobic fatty acid tails are buried in the center away from water.

Steroid hormones

Hydrophobic molecules that can easily pass through the hydrophobic center of the cell surface membrane.

Cholesterol

A membrane component with a polar hydrophilic group and a nonpolar hydrophobic region that stabilizes the membrane, controls fluidity across temperatures, and reduces movement of water-soluble chemicals.

Fluid (in Fluid Mosaic Model)

Refers to the feature of cell membranes where phospholipid molecules can move around within each layer, allowing the membrane to be flexible and change shape.

Mosaic (in Fluid Mosaic Model)

Refers to the pattern formed by various protein molecules studded throughout the phospholipid bilayer, with arrangements that vary like tiles in a mosaic.

Fluid Mosaic Model

The model used by scientists to describe the structure of the cell surface membrane, composed of a flexible phospholipid bilayer studded with a varying arrangement of proteins.