Lipids

The correct option is (B) : Hydrophobic

Hydrophobic indicates that lipids detest water. They are insoluble in water. Water cannot bind to a lipid molecule because lipids are non-polar molecules whereas water is polar. Oils and fats create droplets on the surface of water because non-polar lipids will attach to themselves instead than to one another.

The given question asks us to identify the correct statements regarding lipids. Let's evaluate each statement:

1. Statement (a): "Lipids having only single bonds are called unsaturated fatty acids."
   • This statement is incorrect. Lipids with only single bonds are called saturated fatty acids. Unsaturated fatty acids contain one or more double bonds between carbon atoms.
2. Statement (b): "Lecithin is a phospholipid."
   • This statement is correct. Lecithin is indeed a phospholipid, which is a major component of cell membranes and is involved in lipid metabolism.
3. Statement (c): "Trihydroxy propane is glycerol."
   • This statement is correct. Glycerol, a simple polyol compound, is also known as trihydroxy propane as it contains three hydroxyl (-OH) groups.
4. Statement (d): "Palmitic acid has 20 carbon atoms including carboxyl carbon."
   • This statement is incorrect. Palmitic acid has 16 carbon atoms, not 20, including the carboxyl carbon.
5. Statement (e): "Arachidonic acid has 16 carbon atoms."
   • This statement is incorrect. Arachidonic acid actually has 20 carbon atoms.

Based on the evaluation above, the correct statements are (b) and (c). Thus, the correct answer is: