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org16 Fatty acids building units of fats
In an earlier experiment you have molten small quantities of spreads like butter, Becel, dietary magarine and "Du darfst" in a syringe.
Due to it lower density the fat (as long as it is liquid it is called "fatty oil") floats on the water.
Fig. 1: The fat in "Du darfst" becomes solid during cooling in a syringe. Water also solidifies as it contains gelatine.
The electric conductivities of the fatty layer (Fig. 1 yellow) and of the aqueous layer are tested with a battery and a light emitting diode (LED).
Experiment
1. Make models of a glycerol molecule and of three molecules of fatty acids by welding about 40 black, 65 white and11 read beads..
2. Finally connect these 4 building units to obtain 1 molecule of a fat and 3 water molecules.
Observation
The LED only shows light in the aqueous layer.
Explanation
Salt is only dissolved in the aqueous layer. Its ions are conductors for electricity
Fig.
2:
The
4 building units of a fat molecule are 1
molecule of glycerol (propantriol) and 3 molecules of fatty
acids. Fig. 3: By removing the models of 3 water molecules the 4 building units were connected to make this model of a fat molecule (C35H64O6).