Biology help please

1. Lipids: They are defined as any class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. They are a diverse group of chemicals and include many natural oils, waxes and steroids. They have no singular structure because they encompass a group of compounds however, a fatty acid will always be present. Fatty acids are organic molecules which all have a -COOH group attached to a hydrocarbon tail.

2. Triglycerides: They are the most common type of lipids and are usually known as fats and oils. They are made by the combination of 3 fatty acid molecules and 1 glycerol molecule. Glycerol, as you may know, is a type of alcohol.

3. Phospholipids: They are a special type of lipid and can be thought of as modified triglycerides. One of the 3 fatty acid chains in a triglyceride is replaced by a phosphate group. This makes the molecule soluble in water because the phosphate group is polar/hydrophilic while the remaining fatty acid tails are hydrophobic.

The below image link might make the structural differences clearer.

https://en.wikipedia.org/wiki/Lipid#/media/File:Common_lipids_lmaps.png

Hope this helps

Thankyou so much!