LIPIDS

LIPIDS Fats, oils, phospholipids, steroids & waxes Composed of C, H, O (but fewer O than carbs) Chains of C atoms bonded to each other and to H atoms.

Lipids are HYDROPHOBIC! “Water fearing”(b/c of non-polar C-H bonds in the tail)

Major Roles of Lipids: #1: Used as long-term energy storage. Adipose cells: (fat cells) store energy, cushion vital organs, and insulate the body.

Many organisms can survive w/o steady diets because of stored fat. Fats store energy more efficiently than carbs. (They have more H bonds!) Many organisms can survive w/o steady diets because of stored fat. When there’s lots of food, animals convert excess food into fats. When food is scarce, these can be broken down for energy. https://www.youtube.com/watch?v=7Wbs6DJkwEU

#2 & 3: Form cell membranes & control water movement. Cell membranes are made up of phospholipids. One end likes water, one end is repelled by water. Waxy surface on plants controls water loss.

#4: Used as chemical messengers. Ex. Steroids (testosterone & estrogen)

MONOMERS Lipids are made up of fatty acids Fatty Acids - long chains of C & H atoms that have a carboxyl group (-COOH) at one end. - polar - hydrophilic → “water loving” Have a hydrocarbon group at the other end (CH3) Nonpolar Hydrophobic

Saturated Fats= All C atoms are bonded by a single bond, holding the max number of H atoms. Commonly found in dairy products and meats. Usually solid at room temp.

Unsaturated Fats = A pair of carbon atoms is joined by a double bond, it doesn’t contain the max number of H atoms. Changes the shape, by adding a “kink”

Polyunsaturated = Contains multiple double bonds Polyunsaturated = Contains multiple double bonds. Will be oil at room temp, such as peanut and corn oil.

Phospholipids Consist of hydrophilic and hydrophobic regions. Made up of only two fatty acids, instead of three. Make up cell membranes.