EXPERIMENT #11: PHYSICAL PROPERTIES OF LIPIDS (FATS AND OILS)

Question 1

Are naturally occurring substances that are arbitrarily grouped together on the basis of their insolubility in water (a polar solvent) and solubility in non polar solvents (like chloroform, benzene, ether, etc).

Answer 1

Lipids

Question 2

Glycerides

Answer 2

Esters of glycerol and fatty acids

Question 3

Naturally occurring glycerides are called_____ depending on whether they are solid or liquid at room temperature

Answer 3

Fats or Oils

Question 4

Made up largely of triglycerides containing fully saturated fatty acids with straight chains and an even number of carbon atoms

Answer 4

Animal Fat

Question 5

Obtained primarily from animals, and contain a larger proportion of saturated fats

Answer 5

Fats

Question 6

Obtained primarily from plants and contain a greater proportion of unsaturated fatty acids

Answer 6

Oils

Question 7

Simple test for lipids that has been used for centuries

Answer 7

Grease-Spot Test

Question 8

A long chain base that is the backbone of sphingolipids

Answer 8

Sphingosine

Question 9

Lipids that are derived from_____ and _____ , will produce translucent “spots” or “stains” on fabrics

Answer 9

Glycerol, Sphingosine

Question 10

The grease-spot test requires that the lipid be in____ form

Answer 10

Liquid

Question 11

Lipids are insoluble in water and when mixing lipids with water temporarily mixed and after a few minutes the water and lipids are separated as two layers by a process known as

Answer 11

Emulsification

Question 12

The best emulsifying agent is

Answer 12

Bile salt and lecithin

Question 13

The hydrophobic (non-polar) tail of the emulsifying agents directed to the oil drop while hydrophilic (polar) head directed to water and forming a

Answer 13

Micelles molecule

Question 14

Physical property shared by all lipids

Answer 14

All lipids contain both a hydrophilic and hydrophobic component. They share a trait of atleast partially hydrophobic

Question 15

Why are lipids insoluble in water?

Answer 15

Lipids are insoluble in water because lipids are non-polar while water is polar

Question 16

Which type of molecules are lipids mostly made of?

Answer 16

One glycerol molecule that is joined to three molecules of fatty acids, either saturated and unsaturated, through ester bonds