Feminism Contribution - Structure, Bonding and Classification

Structure, Bonding and Classification

Lipids

Lipids are a large diverse group of naturally occurring organic compounds that are related by their solubility in nonpolar organic solvents and general insolubility in water.  They have a great structural variety.

All lipids contain carbon, hydrogen and oxygen.

Properties of lipids

All lipids are insoluble in water.

Lipids do dissolve in organics solvents such as acetone and ethanol.

There are 2 types of lipids:

• Fats
• Oils

Fats are solid at room temperature (10-20°C) and Oils are liquids at room temperature (10-20°C).

Lipids are made up of an alcohol (usually glycerol) and a number of fatty acids.

Glycerol has 3 hydroxyl groups (-OH) each of which combines with a separate fatty acid.

This results in the formation of a triglyceride. The fatty acids in a triglyceride may be all the same or different.

Structure of Triglyceride

[pic 1]

This combination of fatty acids and glycerol is known as a condensation reaction with the with the OH group of the alcohol backbone. It also results in the formation of water. Most naturally occurring lipids contain the same alcohol (glycerol).

Structure of Glycerol

[pic 3][pic 2]

As glycerol occurs in most lipids it is the nature of the fatty acid which determines the characteristic of any particular fat.

Fatty Acids

Fatty acids are composed of an acidic carboxyl (COOH) group and a large hydrocarbon (hydrogen and carbon) chain of variable length.  Most fatty acids are made up of between 14 and 16 carbons.

There are 2 types of fatty acids:

• Unsaturated fatty acids
• Saturated fatty acids

Structure of each type of Fatty Acid

[pic 5][pic 4]

Unsaturated fatty acids contain one or more double bonds between the carbon atoms. Saturated fatty acids contain only single bonds between the carbon atoms.