Lipids, Proteins, and Biological Molecules

A set of vocabulary flashcards covering key topics on lipids, triglycerides, fatty acid structures, phospholipids, steroids, and proteins based on lecture slide notes.

Lipids

A diverse group of water-insoluble molecules composed of long nonpolar hydrocarbon chains with a relative lack of hydrophilic functional groups, used for long-term energy storage and waterproofing.

Triglycerides

Molecules that make up fats and oils, formed when the carboxyl portions of three fatty acids react with the $\text{-OH}$ groups of glycerol.

Glycerol

A three-carbon chain containing three $\text{-OH}$ groups that serves as one of the two subunit molecules in a triglyceride.

Fatty Acid

A subunit molecule of fats and oils consisting of a long chain of carbon atoms bonded only to hydrogen, with a carboxyl group at one end.

Synthesis and Breakdown of Fat

The reaction process where one glycerol and three fatty acids combine via dehydration synthesis to form fat and three waters ($3\,\text{H}_2\text{O}$), or break down through hydrolysis.

Unsaturated Fats

Fats containing double bonds in the carbon chain wherever the number of hydrogen atoms is less than two per carbon atom.

Saturated Fatty Acids

Fatty acids that have no double bonds between carbon atoms in their carbon chain.

Trans Fat

An unsaturated fat whose double bond has hydrogen ($H$) atoms located on opposite sides of the bond.

Fatty Acid Structural Types

Structural types of fatty acids, including unsaturated fatty acids with a bend ($C_{18}H_{34}O_2$), saturated fatty acids ($C_{18}H_{36}O_2$), and unsaturated trans fats ($C_{18}H_{34}O_2$).

Phospholipids

Lipids that form the bulk of the plasma membrane, featuring a water-soluble polar phosphate head and non-water-soluble nonpolar fatty acid tails.

Polar Phosphate Head

The water-soluble end of a phospholipid molecule.

Nonpolar Fatty Acid Tails

The end of a phospholipid molecule that is not water-soluble.

Steroids

Lipids made of four fused rings that contain no fatty acids, are insoluble in water, are derived from cholesterol, and differ only in their functional groups.

Proteins

Biological macromolecules composed of amino acid monomers that carry out support, metabolism, transport, defense, regulation, and motion.

Amino Acid

The monomer building block of proteins, consisting of a central carbon atom bonded to a hydrogen atom, an amino group, a carboxyl group, and a side chain or R group.