LipidsLipids

Characteristics of LipidsCharacteristics of Lipids

NONPOLAR (neutral)NONPOLAR (neutral) DO NOT dissolve in water DO NOT dissolve in water

Hydrophobic Hydrophobic • (at least part of the molecule)(at least part of the molecule)

Will dissolve in Will dissolve in

nonpolar solvents nonpolar solvents

like ______like ______

EmulsifiersEmulsifiers

Can cause fats to mix with waterCan cause fats to mix with water Have polar and nonpolar endsHave polar and nonpolar ends Surround oil droplets with polar ends out to Surround oil droplets with polar ends out to

dissolve in waterdissolve in water• Ex- soaps and detergentsEx- soaps and detergents

Fats and OilsFats and Oils

made of glycerol and fatty acidsmade of glycerol and fatty acids Called-TRIGLYCERIDE:Called-TRIGLYCERIDE:

Made of a glycerol and 3 fatty acidsMade of a glycerol and 3 fatty acids linked through dehydration synthesis linked through dehydration synthesis

reactionsreactions

Fatty acids can be saturated or Fatty acids can be saturated or unsaturatedunsaturated

Saturated Fatty Acids have no double Saturated Fatty Acids have no double covalent bonds between carbon atoms.covalent bonds between carbon atoms. (the C chain is “saturated” with all the H’s it (the C chain is “saturated” with all the H’s it

can hold)can hold) Solid at room temperatureSolid at room temperature

• Ex- butterEx- butter

Fatty acids can be saturated or Fatty acids can be saturated or unsaturatedunsaturated

Unsaturated Fatty Unsaturated Fatty Acids Acids havehave double double covalent bonds covalent bonds between carbon between carbon atoms.atoms. Liquid at room Liquid at room

temperaturetemperature• Ex- oilsEx- oils

Hydrogenated?Hydrogenated?

Ever heard of hydrogenated fats? What Ever heard of hydrogenated fats? What do you think this means?do you think this means? Manufacturers add H’s to make fats saturatedManufacturers add H’s to make fats saturated

• Allows them to be solid and last longerAllows them to be solid and last longer• Can create TRANS FATSCan create TRANS FATS

Today show on fats

Kinds of LipidsKinds of Lipids

Fats and OilsFats and Oils

PhospholipidsPhospholipids

SteroidsSteroids

PhospholipidsPhospholipids

Have a phosphate in place of a fatty acidHave a phosphate in place of a fatty acid

PhospholipidsPhospholipids

Not electrically neutral like fatsNot electrically neutral like fats Have a POLAR HEAD (because of the Have a POLAR HEAD (because of the

phosphate ion) and a NONPOLAR TAILphosphate ion) and a NONPOLAR TAIL This property determines the structure of a This property determines the structure of a

cell membrane as we will see soon cell membrane as we will see soon

Kinds of LipidsKinds of Lipids

Fats and OilsFats and Oils

PhospholipidsPhospholipids

SteroidsSteroids

SteroidsSteroids

Backbone of 4 fused Carbon ringsBackbone of 4 fused Carbon rings

Ex- cholesterol (also important in cell Ex- cholesterol (also important in cell membranes)membranes)

What kind of lipid is shown below?What kind of lipid is shown below?

Fat

/Oil

Ste

roid

Phosp

holipid

33% 33%33%

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1.1. Fat/OilFat/Oil

2.2. SteroidSteroid

3.3. PhospholipidPhospholipid

How would you describe the fatty How would you describe the fatty acid below?acid below?

.

.

.

..

1.1. HydrogenatedHydrogenated

2.2. SaturatedSaturated

3.3. UnsaturatedUnsaturated

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