Lipids Lecture Flashcards

Vocabulary practice flashcards generated from the lecture transcript covering the characteristics, classes, structures, and behavior of lipids.

Lipids

A chemically diverse group of biological molecules defined by their property of being largely non-polar and highly hydrophobic, composed primarily of carbon and hydrogen, and not structured as polymers.

Hydrocarbons

Molecules composed exclusively of carbon and hydrogen atoms.

Triacylglycerol

Also known as a triglyceride or fat, a lipid composed of three fatty acid molecules connected by ester bonds to a single glycerol backbone, serving primarily as energy storage.

Steroids

A class of lipids characteristically composed of many carbon atoms bonded together to form ring structures, with examples including cholesterol and estradiol.

Phospholipids

Lipids composed of a glycerol backbone, two fatty acid tails, and a phosphate-containing head group, acting as the fundamental structural component of cell membranes.

Glycerol

A three-carbon molecule containing three hydroxyl functional groups that acts as the backbone for triacylglycerols and phospholipids.

Fatty acids

Molecules containing long unbranched chains of carbon atoms that terminate with a carboxyl functional group.

Saturated fatty acid

A fatty acid in which all carbon-carbon bonds are single bonds, allowing the molecule to remain straight, pack tightly, and be solid at room temperature due to its high melting temperature.

Unsaturated fatty acid

A fatty acid containing one or more double bonds in its carbon chain, which introduces rigid kinks that prevent tight packing, causing it to have a lower melting temperature and remain liquid at room temperature.

Hydrogenated oils

Substances created by chemically breaking double bonds in unsaturated fats and adding hydrogen atoms to alter their physical structure and consistency at room temperature.

Amphipathic molecules

Molecules, such as phospholipids, that contain both hydrophilic (water-loving) and hydrophobic (water-fearing) regions.

Phospholipid bilayer

A sheet structure two molecules thick that spontaneously forms in an aqueous environment, where hydrophobic fatty acid tails aggregate in the core to exclude water while hydrophilic heads face outward.