Lipids, a need to know...
What is a lipd?
Lipids, or as they are more commonly known - fats, are organic molecules. They are made up of Carbon, Hydrogen and Oxygen. They differ from Carbohydrates in that they have different ratio of Oxygen. They have a general formula of C1:H2:O a little bit. Ok, not amazingly scientific, but it really is only a small amount per molecule. Depending on the bonding, they can be either solid (fats) or liquid (oils) although, more on that later.
Glycerol is one of two molecules which make up a Triglyceride (a type of lipid). Glycerol, as the 'ol' suggests is an alcohol, which means it has an OH functional group. Actually, it has three OH groups just to spice things up a tad. It has a general formula of C3H8O3 or propan-1,2,3-ol for the budding chemists out there.
As the diagram nicely indicates, glycerol is an alcohol, with three Carbons and three OH groups, the rest of the bonds are taken up with Hydrogens.
As un-scientific as that sounds, 'fatty acids' is a technical term and you wont get marked down for using. Stress not. Fatty acids have a general formula of CnH2nCOOH. However, the best one (most scientificly correct) is: CH3(CH2)nCOOH. If asked, try remember the latter.
Here is an example of a fatty acid:
As you can see, they are pretty whughe. They are very, very, very, very long carboxcylic acids, as denoted by the COOH functional group in both the general and displayed (picture above) formulas.
Another example of a fatty acid:
Wowza, snazy picture or what! Anyways, as you can see, palmitic acid is exactly the same as stearic acid, it just has a shorter hydrocarbon chain in the middle. Not quite sure…