AP Bio Unit 1: Chp 3: Carbon and the Molecular Diversity of Life (Lipids)

Lipids

Fats, Phospholipids, and Steroids; Don't form true polymers, are hydrophobic because they consist mostly of hydrocarbons which form nonpolar covalent bonds (very few oxygen atoms)

Fats

Made up of two smaller molecules: glycerol and fatty acids

Glycerol

3-carbon alcohol with a hydroxyl group attached to each carbon

Fatty Acid

Carboxyl group attached to a long carbon skeleton (hydrophobic)

Monomer unit of Lipids

Glycerol and 3 fatty acids joined by -ester linkage, creates a triacylglycerol or triglyceride

Saturated fatty acids

have the maximum number of hydrogen atoms possible and no double bonds, typically solid at room temp

Unsaturated fatty acids

have 1 or more double bonds, typically liquid (move); double bonds "link" structure prevent it from solidifying

Phospholipids

2 fatty acids and a phosphate group are attached to glycerol; the 2 fatty acid tails are hydrophobic but the phosphate group forms a hydrophilic head

Cell membrane is made up of

Phospholipid bilayer, hydrophilic head and hydrophobic tails

Steroids

lipids characterized by a carbon skeleton consisting of 4 fused rings

Cholesterol

A steroid, component in animal cell membranes