Biology 1

Lipids: Fats

Biology 1

LipidsConcentrated energy molecules

Biology 1

Lipids Composed of Carbon, Hydrogen, and

Oxygen. Have a higher ratio of carbon and

hydrogen to oxygen compared to carbohydrates. This means they store more energy per

gram

Biology 1 2003-2004

Lipids

Function: energy storage

very concentrated twice the energy as carbohydrates!

cell membrane cushions organs insulates body

think whale blubber!

Biology 1

Lipids Lipids are NONPOLAR They do not mix with water Ex: oil and water

Biology 1

Fatty Acids Unbranched carbon chains that make

up most lipids Long carbon chain with a carboxyl

group (-COOH) attached at one end

Biology 1

Lipids Three classes of lipids that contain

fatty acids: Triglycerides Phospholipids Waxes

Biology 1

Triglyceride 3 fatty acids attached to a molecule of

glycerol

Biology 1

Phospholipids Have 2 fatty acids attached to a molecule

of glycerol. Cell membranes are made from

phospholipids heads are on the outside touching water

“hydrophillic” tails are on inside away from water

“hydrophobic” forms a barrier

between the cell & the outside

Biology 1

Phospholipid Bilayer

Biology 1

Waxes Type of structural lipids consisting of a

long fatty acid chain joined with a long alcohol chain.

Waterproof Form protective cover on outside of

plants Used as protective layer in animals

Earwax-helps microorganisms for entering ear canal.

Biology 1

Steroids No fatty acids Four fused carbon rings with various

functional groups Testosterone and estrogen Cholesterol- needed for nerve cells and

other functions Too much cholesterol may

lead to blockage and

heart disease.

Biology 1

Saturated Fat vs. Unsaturated Fat

Biology 1

Saturated fats Most animal fats

solid at room temperature

Limit the amount in your diet contributes to

heart disease deposits in

arteries

Biology 1

Saturated Fat

Always has carbon atoms that are each bonded to 4 other atoms.

Biology 1

Unsaturated fats Plant, vegetable & fish fats

liquid at room temperature the fat molecules

don’t stack tightlytogether

Better choice in your diet

Biology 1 2003-2004

Saturated vs. unsaturatedsaturated unsaturated

Biology 1 18

Summary of FatsSaturated UnsaturatedSingle bond (straight) Double bond

(kinked)Solid Liquid

Animal (cholesterol) Plants (cholesterol free)

Flaky Tenderization

“Unhealthy” Essential Fatty Acids and ώ-3s

Chemically stable D.B.s reactive, free radicals

Cooling as Solidliquid