Triglycerides and all that jazz.

Obj- To be able to draw and label the components of a Triglyceride.

Lipids - Biochem of Biological Molecules.

Lipids are a diverse collection of substances. They are an excellent energy store. Hibernating animals use them to store nutrients as fats. They are found in seeds/the fruit of a plant.

They are used for:

1. Energy Storage.
   
2. Insulation - useful, conducts heat slowly.
   
3. Source of metabolic water- fats oxidised in respiration and make water. Deserts animals such as camels store fats as a source of this.

Lipids are not soluble in water, they are in organic liquids though, like ethanol.

A triglyceride, is glycerol, with 3 fats attached.

The difference between an oil and a fat is that an oil is a liquid at room temperature whereas a fat is a solid.

Glyderol is usually called a hydrocarbon, thanks to it's structure:

H
-
H- C - OH
-
H- C - OH
-
H- C - OH
-
H

If there are 3 hydrogens attached to a carbon, this structure is called a Methyl group. The -OH is a Hydroxyl group, wihch is the one found in alcohols. Therefore, Glycerol is a three carbon, alcohol molecule.

Fatty acids are hydrocarbons chains of varying length with a methyl group at one end and a carboxylic acid group at the other.

Methyl is a carbon with three single bonded hydrogens. Carboxylic acids is an 'Oh' single bonded to a carbon, with a double bonded oxygen.

COOH, means something is an acid.

Saturated fatty acid = Get a fat in triglyceride. (Yea, I don't get this bit of my note. Kersplain, someones?)

Unsaturated: Got double bonds, less saturated with 'H' atoms. Not as many particles that can move betweens each other can't become more squished and rigid, so becomes liquid, not solid. Also has a far lower melting point.

[AN: Surely with would mean Fats are saturated and Oils aren't? Yea? Comment and help???]

The more double bonds, the lower the melting point. [WHY?]

A triglyceride forms in a condensation reaction. If you're ever in doubt, write condensation reaction. Or at least, this is what my notes say. Lets go along with that one, shall we?

Anyway, it forms an 'o', or oxygen bond inbetween, which has a name, an esther bond.

To test for lipids, we use the Lipid Emulsion Test. To do this, we:

1. Take the material/sample, and put in the a test tube.
   
2. Add to this approx 2cm[cubed] of ethanol and shake. (Vigorously will do. xP)
   
3. Add 2cm[cubed] of water, and ...
   

If a MILKY EMULSION forms, this is a positive indictation of a lipid's presence.



Like usual, correct me, should I be wrong. I'm only an AS student, as I've said. (:
-Nin.