LIPIDSLIPIDS

The Molecules of CellsThe Molecules of Cells

CH 3CH 3

LipidsLipids

Lipids include fats, which Lipids include fats, which are mostly energy-storage are mostly energy-storage moleculesmolecules

These compounds are These compounds are composed largely of carbon composed largely of carbon and hydrogenand hydrogen They are grouped together They are grouped together

because they are insolublebecause they are insolublein waterin water

LipidsLipids

Fats, phospholipids and waxes include fatty Fats, phospholipids and waxes include fatty acidsacids

Sterols have rigid backbone of four fused Sterols have rigid backbone of four fused carbon rings (do not contain fatty acids)carbon rings (do not contain fatty acids)

Fatty acids composed ofFatty acids composed of Hydrocarbon chainHydrocarbon chain -COOH (carboxyl group)-COOH (carboxyl group)

LipidsLipids Fats are lipids whose main function is energy storageFats are lipids whose main function is energy storage

They are also called triglyceridesThey are also called triglycerides A triglyceride molecule consists of one glycerol A triglyceride molecule consists of one glycerol

molecule linked to three fatty acidsmolecule linked to three fatty acids

Fatty acid

Unsaturated & Saturated FatsUnsaturated & Saturated Fats Unsaturated fats (plant oils) contain double bonds Unsaturated fats (plant oils) contain double bonds

between carbonsbetween carbons Double bonds prevent them from solidifying at Double bonds prevent them from solidifying at

room temperature room temperature

Saturated fats (lard) have single bonds between Saturated fats (lard) have single bonds between carbons, no double bondscarbons, no double bonds They are solid at room temperatureThey are solid at room temperature

Three Fatty AcidsThree Fatty Acids

stearic acid oleic acid linolenic acid

Phospholipids, waxes, and steroids are Phospholipids, waxes, and steroids are lipids with a variety of functionslipids with a variety of functions

Phospholipids are a main Phospholipids are a main component of cell membranescomponent of cell membranes

Waxes form waterproof coatingsWaxes form waterproof coatings Steroids Steroids

are often are often hormones hormones

SterolsSterols Contain no fatty acidsContain no fatty acids Backbone form by four fused together carbon rings Backbone form by four fused together carbon rings Cholesterol – most common type found in animalsCholesterol – most common type found in animals