Triglycerides.

https://www.youtube.com/watch?v=TPEQBB_u4tc

What are lipids

Name for molecules found in fats and oils

Functions of lipids

Major source of energy in human diet

They also store energy

Used as waterproofing, e.g oils which coat the feathers of aquatic birds

Major part of the structure of membranes, such as those which surround cells and mitochondria

What is the general structure of a triglyceride (type of lipid)

Contains a molecule of glycerol bonded to three fatty acid molecules.

What are two key parts to fatty acid molecules

At the end , we have a carboxylic group

The rest of molecule consists of a long chain of carbon atoms bonded to hydrogen

What is saturated fatty acid

They contain only single covalent bonds between carbon atoms ,

What is unsaturated fatty acid

They have at least one double covalent bond between carbon atoms. This is monounsaturated fatty acid as there is only one double covalent bond in carbon chain. If it has more than one double covalent, it is polyunsaturated,

What does glycerol molecule contain

Three hydroxyl groups

How is triglyceride formed

1 glycerol reacts with 3 fatty acids to form an ester bond, this process is called esterification, water is also made (condensation reaction)

This reaction is carried out 2 more times with 2 more fatty acid molecules to form structure of triglyceride molecule.

Important points about triglycerides

They are non polar molecules meaning they’re hydrophobic, so do not dissolve in water

Because triglycerides contain large number of carbon and hydrogen atoms, a great deal of energy can be released from triglycerides.