LIPIDSLIPIDS

LIPIDSLIPIDS•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)

3 Major Roles of Lipids: #1: Used as long-

term energy storage.

Adipose cells: (fat cells) store energy, cushion vital organs, and insulate the body.

• 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.

#2: Form biological 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.

•#3: Used as chemical messengers. –Ex. Steroids (testosterone & estrogen)

Testosterone

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.

•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. 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.