We have all been introduced to this topic atleast once before, even if it was not school related we all knew that when someone said lipids they were talking about something fat related. Some common structures of lipids would be :
Fats and oils. (triglycerides)
Fats are solids at room temperature, but oils are liquids
Fats contain SATURATED hydrocarbon chains
Oils contain UNSATURATED hydrocarbon chains, this just means that they contain atleast 1 C-C double bond.
They are lipids and their molecules have single hydrocarbon chains that are linked to an alcohol
Really important in fruits for two reasons:
1. Protective layer in fruits, vegetables
2. Added in some cases for appearance and protection
Functions and Properties
- source of energy
- energy reserve, bascially if there is any excess energy from carbohydrates , proteins and lipids they are stored as TAG in adipose tissues
- Provide insulation for the body
- Protects vital organs
- helps in the formation of cell membranes
- steroid hormones
- flavor and taste
All carbons are bonded to H
there is no C-C double bond
they form long straight chains
solid at room temperature
Mostly animal fats
They contain C-C double bonds
Found in plant and fish fats
They are liquids at room temperature
Because of the presence of the double bonds they form kinks in the hydrocarbon chains, and this prevents the molecules from packing tightly together.
Effect of the double bond on Fatty acids
As the length of the fatty acid chain increases, the melting point of the fatty acid would increase but the solubility will decrease.
Stearic aicid and Linoleic acid both have the same number of carbon atoms but because of the presence of double bonds in Linoleic acid their melting points would vary.
Essential Fatty acids
They are the fatty acids that the body cannot produceor synthesize on its own, two examples are Omega – 3 alpha – linolenic acid and Omega – 6 Linoleic acid.
Omega 3 Fatty acid
It is a cis isomer
Found in flaxseed, soybean oil, walnuts, some leafy green vegetables.
Omega 6 Fatty acids
It is a cis isomer
Found in seed nuts, common vegetable oils , sunflower seed, cottonseed.
Nonessential fatty acids – can be made in the body so it is not required in the diet.
References : Biochem Jm youtube channel , video on Lipids part one.