Draw all the possible triacylglycerols that can be constructed from glycerol, palmitic acid, and oleic acid. rank them in order of increasing melting point.

The structure of glycerol, palmitic acid and oleic acid is attached below. 

For the sake of simplicity, palmitic acid and oleic acid is abbreviated as 'O' and 'P', respectively. 

There are six different triacylglycerols can be constructed, from glycerol, palmitic acid, and oleic acid.

Qualitative structure of these triacylglycerols is represent in terms of 'P' and 'O'. 
                     OOO, OOP, OPO, PPO, POP, PPP 

Further, melting point of saturated fatty acid is greater as compared to unsaturated fatty acid. In present case, palmetic acid is saturated, while oleic acid is unsaturated (see structure below)

Thus, all possible triacylglycerols that can be constructed from glycerol, palmitic acid, and oleic acid, in order of increasing melting point are as follows:
                        OOO < OOP ≈ OPO < PPO ≈ POP < PPP  

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