Phospholipids and Membrane Structure

Flashcards covering key concepts related to the structure and function of phospholipids and membranes.

Phospholipids

Fats that form the phospholipid membranes surrounding cells and organelles, composed of two fatty acids, glycerol, and a phosphate group.

Amphipathic

Molecules that have both a polar, hydrophilic end and a non-polar, hydrophobic end, like phospholipids.

Hydrophilic

Describes a substance that is attracted to water; the head of a phospholipid is hydrophilic due to the phosphate group.

Hydrophobic

Describes a substance that repels water; the tails of phospholipids are hydrophobic and non-polar.

Micelles

Structures formed by phospholipids in an aqueous solution that exclude water from their hydrophobic tails.

Integral proteins

Proteins that span the entire phospholipid bilayer and are embedded within the membrane.

Peripheral proteins

Proteins that are located on one side of the phospholipid membrane, not spanning the membrane.

Fluidity

The ability of the phospholipid bilayer to allow movement of lipids and proteins; influenced by fatty acid chain structure and temperature.

Lipid bilayer

A double layer of phospholipids that constitutes the cell membrane, allowing it to be selectively permeable.

Cholesterol

A type of lipid that strengthens cell membranes at high body temperatures and is a precursor to steroid hormones.

Waxes

Lipids similar to triglycerides, made of fatty acids bonded to long-chain alcohols, providing waterproofing and protection.

Steroids

Lipids characterized by a structure of four carbon rings, found in hormones like estrogen and testosterone.