Lipids, Proteins & Nucleic Acids

Saturated Fat

A fat with no double bonds; solid at room temperature.

Unsaturated Fat

A fat with double bonds; liquid at room temperature.

Oil

An unsaturated fat that is liquid at room temperature.

Steroid

A type of lipid with a four-ring structure, includes hormones.

Cholesterol

A steroid important for animal cell membranes.

Phospholipid

The major component of cell membranes; has a hydrophilic head and hydrophobic tails.

Trans Fat

An unhealthy, artificial unsaturated fat.

Protein

A large polymer made of amino acids; performs most of the work in a cell.

Polypeptide

A single, long chain of amino acids.

Amino Acid

The monomer (building block) of proteins.

R side chain (aka R Group)

The unique part of an amino acid that determines its properties.

Primary Structure

The linear sequence of amino acids in a chain.

Secondary Structure

Local folding patterns like alpha-helices and beta-pleated sheets.

Tertiary Structure

The overall 3D shape of a single polypeptide chain.

Quaternary Structure

The structure formed by multiple polypeptide chains assembling.

Lipoprotein

A compound of a protein and a lipid, used to transport fats.

Glycoprotein

A compound of a protein and a carbohydrate, used for cell recognition.

DNA

The double-stranded molecule that stores an organism's genetic code.

RNA

A single-stranded molecule that helps read the DNA code to build proteins.

Nucleic Acid

A biological polymer (like DNA or RNA) that stores genetic information.

Nucleotide

The monomer of nucleic acids, made of a sugar, phosphate, and base.