Lipids

Lipid

Diverse group of compounds that are largely nonpolar in nature

Lipid chemical bonds

Include mostly carbon-hydrogen and carbon-carbon bonds (nonpolar covalent)

Hydrophobic

"Water-fearing"; insoluble in water

Types of lipids

Include fats, oils, waxes, phospholipids, and steroids

Triglyceride structure

A fat molecule consists of glycerol bound to 3 fatty acids

Glycerol

3 carbon molecule with 3 hydroxyl (-OH) groups

Fatty Acid

Long hydrocarbon chain (12-18 carbons) with a single carboxyl (acid) group

Saturated fatty acid

Contains all single bonds (FATS - solid at room temp)

Unsaturated fatty acids

Contains 1 or more double bonds (OILS - liquid at room temp)

Phospholipids

Major constituent of plasma membranes

Phospholipid bilayer orientation

Hydrophilic head groups face the aqueous solution; hydrophobic tails are sequestered in the middle

Steroids

Consist of 4 fused carbon rings

Cholesterol

Important component of animal cell membranes (and precursor to steroid hormones)